Philosophy Week 2
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Liberty University**We aren't endorsed by this school
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PLST 450
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Jan 10, 2025
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1 The Basics of Good Arguments People often have a misconception about arguments. The arguments of everyday conversation are quite different from what we have in mind for this book. When Ben was a doctoral student engaged to his wonderful wife-to-be, Lerisa, he had one of those classic arguments that often take place as two people prepare for marriage. They were sitting in a parking lot arguing, and the more they argued, the louder Ben’s voice grew. As his voice rose, Lerisa looked at him and said, “Arguments aren’t about winning!” It stopped him in the middle of his sentence—not because he suddenly agreed with her side of the argument but because what she said went against everything he believed based on his experience. Growing up in an opinionated family, Ben was conditioned to think that arguing was about winning and that the loudest person always won. What Lerisa revealed to Ben that day stood in sharp contrast to everything he knew about arguing. She pointed out that an argument is not a battle to be fought and won but rather a means for communicating a message. Rich’s family background is similar. He also grew up in the context of a family dynamic in which the loudest, most forceful person “won” the argument. Perhaps your experience is similar and you too have ingrained in your thinking the idea that arguments are like battles to be fought and won, and the loudest, most aggressive combatants win. Perhaps because of experiences like this, you now recoil at the thought of engaging in an argument. It is vital to understand that the conception of argumentation we just described is a misconception. Some people do indeed argue that way, but that isn’t what an argument is all about. Our definition of an argument is the process of giving a systematic account of reasons in support of a claim or belief. Instead of thinking about “winning” an argument, we would do better to think about “winning someone over to our side”—that is, we want to persuade someone that the position we are defending really is true, to convince them so that they genuinely change their mind and come to agree with the position we are defending. We aim to persuade, encourage, and prepare, not to win. And if we can’t thoroughly convince someone that our position is true, we can, at the very least, use effective argumentation to defend our position as a reasonable option among various choices. An argument should never be a shouting match, and the loudest participant doesn’t automatically win. In fact, if our main goal is to bring about genuine persuasion, then shouting is the least likely tactic to bring about this goal. Instead, skillful arguers will learn to give clear, straightforward, easy-to-understand reasons that support a claim, without getting into a rhetorical competition or shouting match. Claims and Beliefs As we consider this perspective on what an argument is, we must recognize at the outset that claims and beliefs go hand in hand. For anything you believe, you can state that belief in the form of a claim. For example, you may believe that a portion of the film The Hunger Games was filmed in North Carolina. It is easy to recognize that belief when you communicate it in the form of a claim. If you are sitting with friends watching the film, you may say something like, “Part of this movie was filmed in North Carolina.” This statement is a claim and communicates what you believe—in this case, what you believe about The Hunger Games being filmed (in part) in North Carolina. We’ll return to the concept of beliefs in a later chapter; for now it is sufficient to recognize that when we communicate our beliefs to others, we state them in the form of claims. So for most of our discussion, we will use the words claim and belief interchangeably. Stating a claim by itself is almost never good enough if we want others to understand why we believe what we believe, or if we want to persuade them that we have good reasons supporting our beliefs. Considering the example above, in some contexts it will probably be insufficient to simply make the claim about where The Hunger Games was filmed. Instead of merely stating the claim, we must provide good reasons that help show why we think that claim is true. Sometimes claims don’t need much in the way of supporting reasons. If you are watching The Hunger Games with a group of friends who don’t think your claim is all that important, they might just accept it without any
supporting reasons, so you probably don’t need to say much else. This is similar to many everyday claims we make. For example, a claim like “It’s raining” doesn’t need much of an argument for support. We can just point out the window and say, “Look! It’s raining.” But for complicated or contentious claims, or claims made to an audience that is inclined to disagree, an argument is needed to justify and support the claim. The more contentious or divisive the claim, the more careful, well-thought-out, and intentional the argument must be. We don’t need to support unimportant or uninteresting claims with good arguments, but for the important questions of life—such as questions about the morality of capital punishment, the existence of God, and the nature of marriage—being able to argue well becomes an indispensable skill. Claims about important questions will always require good arguments to support them. Arguments are beneficial not just for others but for yourself as well; they help you communicate and support your personal beliefs. Essential Features of a Good Argument Good arguments are necessary not just for supporting your claims for the benefit of those who are reading or listening to your argument; they are also important as you begin grappling with your own beliefs. In order to argue well, you must first learn how to develop good arguments by yourself, independent of a discussion with someone else; and if you are able to present a rational defense of a claim palatable enough to quench your own skepticism, it is likely that you will be able to present it to others for their edification as well. But what makes a good argument? At this point it is tempting for us to present an extended discussion of bad arguments and the bad reasoning that goes along with them—because bad reasoning is so common and is often disguised as good reasoning—but we’ll save that for a later chapter. In the remainder of this chapter, we focus on the essential features of good arguments. This is because good reasoning will form the fundamental building blocks of good arguments. In this book’s introduction, we briefly described the basic components of a short argument: an argument contains a series of statements (premises) that are intended to support another statement (the conclusion). An argument’s conclusion is the claim or belief that is being defended or supported by the premises, and the premises are the reasons that attempt to prove that the claim is true. When arguments are written out formally (as they might appear in textbooks on logic), they start by giving the premises and end by stating the conclusion. Written out in sequence, an argument might appear like this: Premise (Reason) 1 Premise (Reason) 2 ∴Conclusion (i.e., the claim or belief that is being defended by these two premises) However, when arguments are written in ordinary prose or stated orally, they don’t always proceed in such a linear order. Sometimes the conclusion is stated first, and sometimes it is stated in the middle of the premises, so it can be difficult to identify the various parts. When arguments are long and complex, it can be even more difficult to identify the parts and see how they fit together. Long arguments often contain arguments inside other arguments, which further complicates the situation. But no matter how short or long, and no matter what order the various items are presented in, all arguments share the same basic components: claims and reasons that support those claims. Good Arguments State Clearly All of Their Essential Elements As we have said, when short arguments are written formally, they often begin with premises and end with the conclusion. Recall the famous example we mentioned in the introduction: All men are mortal. (Premise) Socrates is a man. (Premise) Therefore, Socrates is mortal. (Conclusion) Writing arguments in this form can indeed be quite helpful when we are engaged in analyzing an argument that someone else has given. That is why introductory textbooks on philosophy and logic are full of example arguments written out just like this. In most cases the purpose is to help the student identify the key parts of the arguments and to differentiate good arguments from bad ones. However, many arguments—indeed most arguments—that we encounter are presented outside the context of the logic textbook. They might be given orally as a part of a public policy speech or a sermon. Or they might be written in
ordinary prose in newspaper articles, journals, academic papers, or blog entries. In these varied contexts, it is rather uncommon to have a simple, short argument written out like the one above about Socrates, with two or three premises leading to a simple conclusion. For each argument we encounter, what really matters is whether the essential elements in the argument are stated clearly. No matter the form or the context in which they are presented, good arguments will always clearly state their claims and all relevant supporting reasons. As you learn to develop your own arguments, one of the most important skills to develop is the skill of clearly stating every element that is important to the argument. Some arguments do not state their premises clearly; this is a characteristic of weak arguments that cannot do what they are intended to do. Premises are designed to be declarative statements that convey some meaningful fact in support of the claim. Sometimes, however, a meaningful fact essential to the argument is not stated at all. Such unstated elements are called hidden premises. Consider again our example argument about Socrates. Someone might put it this way: “Socrates is mortal. After all, he is only a man!” When the argument is stated this way, there is one hidden premise: All men are mortal. Many people will be able to grasp this premise intuitively, so the fact that it is hidden in this particular argument may not do too much harm. However, when a hidden premise is controversial, or when the audience is simply ignorant of the hidden premise, the argument is likely to fail at its intended mission of supporting the claim or persuading the audience. Consider this one: “Of course God exists. Just look at the wonderfully intricate beauty in nature.” In this example, there are several hidden premises, most of which are likely to be controversial or unknown to an audience who does not already believe the claim “God exists.” Some of the hidden premises might be: • Intricate beauty is objective and recognizable. • Intricate beauty indicates design. • Design requires a designer. • Given the extent of the intricate beauty in nature, the designer must be very powerful. Hopefully you can see these aren’t the only hidden premises essential to this example argument. Many other premises would need to be stated for this kind of argument to get off the ground. Moreover, most of the hidden premises in this case are so controversial that each would require a persuasive argument of its own for support, which means that almost no one in an objective audience would think that this example argument is good enough when several premises remain unstated and unsupported. Obvious or uncontroversial hidden premises might not make too much of a difference, but failing to state essential premises that are controversial or not obvious to your audience makes for a weak argument. A good argument will not have this weakness. A good argument will clearly state each premise that supports the claim and will not let any other essential premise remain hidden. While some arguments have hidden premises, other arguments fail to clearly state the main claim. Having a hidden claim is probably a bit rarer than having a hidden premise, but it does happen. Consider this example: Perhaps you have overheard a conversation between friends in response to one friend harming the other or committing some fault against the other. The one who is in the wrong might say, “Well, I’m only human!” It might not look like it at first, but this is a kind of argument. The person who says this is asserting that the other person ought to forgive the wrong that has been committed. This is the main claim that went unstated: “You ought to forgive this wrong that I have committed.” So the argument “I’m only human!” is a weak argument, mainly because the main claim is unstated. Of course there are also at least two hidden premises: “all humans commit these kinds of wrongs” and “one ought to forgive faults that are common to all humans.” Good arguments state the main claim clearly, along with all the essential supporting premises. This should be a fairly easy task to accomplish because, when making an argument, we are all aware of our beliefs and claims. Therefore, stating our beliefs and claims clearly is the easiest part of making a good argument. Good Arguments State the Claim Up Front Another factor to consider is the location of the main claim in the argument—
the where and how of stating the claim. Put simply, good arguments state their claim up front, before supporting reasons are given. As we pointed out above, when short arguments are written out formally (as they appear in an introductory logic textbook), they typically state the claim last, as the conclusion. In the context of the logic textbook, the order of elements in the argument is almost always presented solely for the purpose of analyzing the argument. Presenting the premises first and the conclusion last is a convenient way to help students understand what goes into an argument and how to properly identify all the parts. However, when it comes to actually crafting and delivering a good argument to an audience you want to persuade, this linear order is almost always unhelpful. Instead, stating the main claim at the start is more likely to bring about the desired result. In the course of normal conversation, presenting an effective short argument might go something like this: Me: Socrates is mortal. You: Oh, really? How do we know that? Me: Well, Socrates is a man, right? You: Sure. Me: And all men are mortal, aren’t they? You: Yes. Me: Well if Socrates is a man and all men are mortal, Socrates must be mortal. You: Oh! I see! Yes, you are right. Stating the main claim at the very beginning sets the context so that the audience knows where you are headed and understands why the supporting premises are given and how they are connected to the claim. If the claim is not stated clearly at the beginning, the audience is likely to be confused. Imagine if the first part of the argument given was “All men are mortal.” In that case the audience might assume that this is your main point and miss the fact that you are really trying to prove that Socrates is mortal. Consider this alternative discussion: Me: All men are mortal. You: Probably, but how would we know? Me: Hold on a second, let me finish. Socrates was a man. You: Who? Me: Socrates. He was a man. You: Wasn’t he a great philosopher? And what does that have to do with our mortality? Me: You are missing my point! I’m trying to show you that Socrates is mortal. You: Well, why didn’t you just say so? Good arguments eliminate this possible confusion by clearly stating the main claim up front before the supporting ideas are offered. Stating the claim at the very beginning of an argument is especially important for long arguments. We will return to this in a later chapter, but for now it is important to mention two common contexts for making a long, extended argument: the academic research paper and the speech or sermon. In an academic context, the research paper is a work of scholarship in which the author (typically a student) advances an original thesis and supports that thesis with good arguments. The thesis is just the main claim that the author wants to make, and the entire paper is a series of connected arguments that are intended to support the claim (to persuade the reader that the thesis is true). To say it another way, the thesis is the conclusion of the argument. Too often students who do not know how to make good arguments do not even mention the thesis until the conclusion paragraph of the paper. Unfortunately, this means that the professor will have to read the entire paper to know what the main point is and then will need to read it again to evaluate whether the arguments presented adequately support the thesis. Here is a paper writer’s rule of thumb: don’t save the conclusion for the conclusion! A good research paper (like any good argument) will always state the thesis up front—in the introduction to the paper—so that the professor (or any other reader) knows where the paper is going. The same holds true for a speech or sermon. Your audience will appreciate your argument if you clearly state at the outset what belief you are defending or what claim you are attempting to demonstrate is true. It gives your listener the context necessary to follow and understand your argument, which means your argument is more likely to be successful. Good Arguments Properly Connect Premises to the Claim Good arguments require good premises—premises that appropriately support the main claim of the argument and can therefore help persuade an audience that the claim is true. There are two ways that a premise can fail to support the claim well: (1) the premise is false, or (2) the premise does not adequately support the conclusion. Obviously, a false premise can never do a good
job supporting the main claim of an argument, but perhaps you haven’t given much consideration to how a true premise is connected to the claim and whether that connection provides adequate support. Consider this example: Capital punishment is immoral. Studies show that a shockingly high number of those convicted of capital offenses are actually innocent. Moreover, a disproportionate number of minorities are sentenced to death, indicating racial bias in the court system and possibly in policing policies and tactics. In this example the main claim is that capital punishment is immoral. Two premises are offered to support this claim: a high number of convicts are actually innocent, and a disproportionate number of minorities are sentenced to death. Let’s just say for the sake of discussion that those two premises are true. Even though these premises are true, they still do not do a good job in supporting the main claim because they are not properly connected to it. Whether some convicts are innocent and whether minorities are disproportionately sentenced to death are not directly relevant to the question of whether capital punishment itself is immoral. These premises can support other kinds of claims, such as claims about the need to reform the civil justice system in the United States or about racial inequality. But if we want to support the claim that capital punishment itself is immoral, we will need to offer premises that are related to how we determine whether capital punishment is moral or immoral. Arguments like the example above aren’t good arguments because they make mistakes in reasoning. In the example, the argument’s mistake is in presenting premises that are not relevant to the conclusion (and therefore cannot possibly support the claim). Good arguments do not make this kind of mistake in reasoning. In some cases it might appear as if the premise supports the claim, and this calls for careful evaluation of the argument and of whether the premises are relevant. A special term is used to describe good arguments, arguments in which the premises are properly connected to the conclusion. We say that such arguments are valid arguments. When arguments are valid, the premises are relevant to the conclusion and actually give us good reasons to think that the conclusion is true. Sometimes people use the word valid to describe something that is true, but it is important to recognize that when we are analyzing arguments, we do not use the word valid as a synonym for true. A valid argument is simply one that does not make a mistake in reasoning, and therefore the premises are properly connected to the main claim. In fact, an argument can still be valid even if it has false premises and a false conclusion. To say an argument is valid is not to say that it is true. Rather, to say an argument is valid is to say that if the premises are true, they constitute good reasons to think that the conclusion is true because they are properly connected to the conclusion. A valid argument is one that does not make any mistakes in reasoning. A bad argument, on the other hand, does contain a mistake in reasoning (or perhaps many mistakes in reasoning). Fallacy is the word logicians use to refer to a mistake in reasoning, and an argument that contains one or more fallacies is called a fallacious argument. Whether the premises of a fallacious argument are true or false, they do not constitute good grounds for thinking that the conclusion is true because they do not have the proper logical relationship to the conclusion. Sometimes people will use the word fallacy to describe something that is false. However, in the analysis of arguments, the word fallacy or fallacious never means false. In fact, a fallacious argument can have all true premises and a true conclusion. The reason for this is simply that fallacy is only intended to point out a logical mistake in reasoning. Consider this example: I’m sure that God exists. After all, the vast majority of the people in the world believe in God. The claim being made in this argument is that God exists, and the premise being offered is that most people believe in God. Let’s assume for the sake of discussion that both the main claim (God exists) and the supporting premise (most people believe in God) are indeed true. Even though every element in the argument is true, this is still a fallacious argument. No matter how popular it is to believe in God, this can’t help us determine whether God
actually exists (as if God’s existence depends on a popularity contest). To say that an argument is fallacious is not to say that any part of it is false. Instead, it is simply to say that the premises of the argument do not have the proper relationship to the conclusion—that it makes some kind of mistake in reasoning. We will return to the discussion of fallacies in a later chapter. There we will describe some of the more common fallacies that appear in arguments, show why they are fallacies, and give some tips on how to avoid them. Hopefully this process will help you learn the skill of properly connecting the premises in your argument to the claim you want to make so that you can avoid the more common mistakes in reasoning. Meanwhile, it is sufficient to recognize that fallacious arguments are those that make mistakes in reasoning (their premises are not properly connected to their main claims), and valid arguments are those that do not make mistakes in reasoning. Conclusion This chapter has laid the foundations for the remainder of the book. We have defined the two main parts of an argument: the main claim (which is called the conclusion of an argument) and the reasons that support the conclusion (called the premises). We pointed out that good arguments will always state their premises and claims clearly, and they will almost always state the main claim at the beginning of the argument so that the audience knows where the argument is headed. We also highlighted the importance of having premises that are properly connected to the claim. We pointed out that valid arguments have premises that are properly connected to the claim, while fallacious arguments do not. In the next chapter we will explore two kinds of reasoning, inductive and deductive, and we will give a brief overview of what are sometimes called “the laws of logic.” 2 Reasoning and Logic In the previous chapter we discussed the features of good arguments. After briefly discussing the definition of an argument and the connection between beliefs and claims, we mentioned foundational principles for crafting a good argument: • State clearly all of the essential elements in the argument. • State the main claim up front. • Make sure all premises are properly connected to the main claim. In this chapter we begin by describing the two basic kinds of good arguments, and then we devote some discussion to logic. Two Kinds of Good Reasoning: Deductive and Inductive Previously we explained the importance of an argument having premises that are properly connected to the claim being made. The skill that we employ to make these proper connections is the skill of reasoning. If we want to craft a good argument, we must use good reasoning skills to present premises that are properly related to the claim we are making. There are two basic types of good reasoning: deductive and inductive. Using good deductive reasoning helps us to create good deductive arguments. Using good inductive reasoning helps us to create good inductive arguments. Deductive Arguments Deductive arguments employ deductive reasoning to present premises that support the conclusion. The simplest way to describe deductive reasoning is to say that a good argument using deductive reasoning leads to a conclusion that cannot possibly be false, assuming that all the premises are true. In the study of reasoning and argument, valid is the term used to describe a good deductive argument. As we mentioned in the previous chapter, in everyday language people will sometimes use the word valid to mean true. This is not how we use it here. To say that an argument is valid simply means that the premises are properly connected to the conclusion. A valid deductive argument is one in which, if the premises are true, the conclusion is certainly true. The argument about Socrates that we have repeated several times is an example of a valid deductive argument. Here it is again: All men are mortal. (Premise) Socrates is a man. (Premise) Therefore, Socrates is mortal. (Conclusion) One key feature of valid deductive argumentation should be noted at this point: in a valid deductive argument, everything about the conclusion is already stated in the premises. In other words, the conclusion to a valid deductive argument does not add any new information; it is simply the natural consequence of the premises being true. Once we grasp the idea that all men are mortal and that
Socrates is a man, we need not add any new information at all to understand that Socrates is mortal. The conclusion is certain, and all the information we need is stated in the premises. Here is another example of a valid deductive argument, this one about presidential elections: If George W. Bush was elected in the 2000 presidential election, he would be the forty-third president of the United States. George W. Bush was elected president in the 2000 election. Therefore, George W. Bush became the forty-third president of the United States. This is a valid deductive argument. The two premises are properly connected to the conclusion, and they contain all the information we need in order to know that if the premises are true, the conclusion is certainly true. In this example, since both premises are true, we know for certain that the conclusion is true. This is what deductive arguments look like: as long as the argument is valid and the premises are true, the conclusion is certainly true. There is, quite literally, no doubt about it. Unfortunately, valid deductive arguments often contain false premises. It is important to emphasize again that valid does not mean true. Valid arguments are those whose premises are properly connected to the conclusion, whether they are true or false. Here is an example: All past presidents of the United States were born before 1941. Bill Clinton was president of the United States. Therefore, Bill Clinton was born before 1941. This too is a valid deductive argument. The two premises are properly connected to the conclusion—that is, they contain all the information we need to know that, if they are true, the conclusion is certainly true. But let’s say we also happen to know that George W. Bush (a past president) was born in 1946. This information tells us that the first premise of this argument must be false. Since that premise is false, it cannot help us establish the conclusion. So while we can be sure that the conclusion of a valid deductive argument is true if the premises are true, the fact that some premises may be false leaves room for doubt about the conclusion, even when the argument’s form is valid. Some valid deductive arguments contain false premises and a false conclusion. The argument about Bill Clinton is a good example of this because Bill Clinton was born in 1946. Here is another example—this one from the New Testament: Nothing good can come from Nazareth. Jesus came from Nazareth. Therefore, Jesus is not good. Again, this is a valid argument: if the premises are true, then the conclusion is certainly true. However, this argument has one true premise, one false premise, and a false conclusion. It is true that Jesus grew up in Nazareth, so premise 2 is true. However, we have other well-established reasons to think that the conclusion is false. Jesus’s goodness is perhaps one of the least-debated facts in all of human history. If we know that Jesus is good, then this alone is reason to reject the first premise. But we probably wouldn’t have to work too hard to come up with another example of something good that came out of Nazareth. So even though this argument is valid, it has one false premise and a false conclusion. Some valid deductive arguments contain one or more false premises, but unlike the previous two examples, they still have true conclusions. Consider this example: The capital of Pennsylvania is the home of the Pittsburgh Steelers. Pittsburgh is the capital of Pennsylvania. Therefore, Pittsburgh is the home of the Pittsburgh Steelers. This is a valid deductive argument. The premises offered contain all the information necessary to lead to a certain conclusion. If the two premises are true, then the conclusion is certainly true. But, as we hope you already know, both premises are actually false. Harrisburg, not Pittsburgh, is the capital of Pennsylvania, and the capital of Pennsylvania is not the home of the Pittsburgh Steelers. But the conclusion is indeed true: Pittsburgh is the home of the Pittsburgh Steelers. So this is an example of a valid deductive argument with two false premises and a true conclusion. So far we have provided examples of valid deductive arguments with true premises and a true conclusion, with false premises and a false conclusion, and with false premises and a true conclusion. However, a valid deductive argument can never have true premises and a false conclusion. This is part of what it means to be a valid deductive argument: if the premises are true, then the conclusion is certainly true. If we
already know that the conclusion of the argument is false and that the premises are true, then we know that it can’t be a valid argument. “If … Then” Deductive Syllogisms A syllogism is a particular kind of deductive argument that has two premises and a conclusion; each of the two premises share a common term that isn’t in the conclusion. While there are many particular kinds, or forms, of syllogisms, two of them are so common that it is worth describing them here. Once you learn their basic structure and how to recognize them, you will probably begin to see them in all kinds of arguments and perhaps even in your own thinking. These two forms both make use of “if … then” statements. In each of the following two argument forms, we use two letters, A and B, to stand for any two content statements. It doesn’t really matter what they are because we are just looking at the form of the arguments, not the particular content. The two forms are referred to by their Latin names, modus ponens and modus tollens. Form of Argument Modus Ponens Modus Tollens Premise 1 If A, then B If A, then B Premise 2 A Not B Conclusion Therefore, B Therefore, not A Any argument that takes one of these forms is a valid deductive argument. The name of the first form, modus ponens (often abbreviated MP), means “mode of affirming.” It gets this name because it affirms a condition (A) that would guarantee the conclusion (B). Stated differently, it says that if A is true, then B is true; A is true; therefore B is also true. Notice that this fits perfectly with our established description of a valid deductive argument: even if one or more of the premises is false, the argument is still valid; if the premises are true, the conclusion is certainly true; and all the information in the conclusion is already contained in the premises. The example argument above about George W. Bush becoming the forty-third president of the United States took the form of MP. We could also rework our old argument about Socrates to fit this form: If Socrates is a man, he is mortal. Socrates is a man. Therefore, Socrates is mortal. The name of the second form, modus tollens (often abbreviated MT), means “mode of denying.” It is given this name because it seeks to deny the content in the conclusion by denying a condition that is necessary to guarantee the conclusion. Stated differently, MT begins the same way as MP by saying that if A is true, then B is also true; but then it denies that B is true, which leads to the conclusion that A must not be true. Here is a common argument for God’s existence that takes the form of MT: If God does not exist, then objective moral values do not exist. Objective moral values do exist. Therefore, God exists. In this example, we see the form of MT. In the first premise, A is “God does not exist”; B is “Objective moral values do not exist.” In the second premise, “not B” is “It is not true that objective moral values do not exist,” and when we eliminate the double negative, it becomes more simply “Objective moral values do exist.” In the conclusion, “not A” is “It is not true that God does not exist,” or more simply “God exists.” Inductive Arguments We have shown that one key feature of a valid deductive argument is that if the premises are true, the conclusion must be true. We saw earlier in this chapter that the conclusion of a valid deductive argument cannot possibly be false (assuming all the premises are true). This leads us to one of the most important differences between deductive and inductive reasoning. In an inductive argument, even if the premises are all true, the conclusion is still not certain. While deductive arguments lead to a certain conclusion, inductive arguments lead only to a probable conclusion. Therefore, a valid inductive argument still has room for doubt as to whether the conclusion is true. One way to think of inductive reasoning is to think about the process of gathering good evidence to make a case. Even though you can’t be 100 percent sure that the conclusion is true, a good inductive argument can give you many good reasons to think that the conclusion is indeed true. To see the difference between this and a deductive argument, think back to a key feature of deductive arguments. We saw above that in a deductive argument the premises clearly state all the information we need in order to know that the conclusion is true. The conclusion of a deductive argument doesn’t add any new information; instead, it restates the information already
present in the premises. Our example argument about Socrates should refresh your memory about this point. The conclusion of the argument (Socrates is mortal) doesn’t add any information. Instead, it is just the natural consequence of the information already presented in the premises. With those key points in mind, we can more easily see a difference in inductive arguments. In inductive arguments a leap must be made. Good evidence is presented, but some information is still missing. Consider this example: This horse has four legs. That horse has four legs. That other horse has four legs. Therefore, all horses have four legs. In this example, we see that even if all the premises are true, we still can’t be 100 percent sure that the conclusion is true. A leap is made between the premises and the conclusion. We see that the three horses sampled do indeed give us good reason to think that “having four legs” is a common feature of all horses, not just these three. But even so, we can’t be sure. The conclusion has information that is not contained in the premises: the conclusion of the example above makes a statement about all horses, even though we have actually seen only three horses. So we have been led to a probable conclusion, not a certain one. Political polling results offer another example of an inductive argument. During a campaign for an election, you will often read something like, “Candidate x enjoys the support of 50 percent of all voters, while candidate y has the support of only 25 percent of the voters, and 25 percent are undecided.” Let’s say that the conclusion of the argument is that “50 percent of all voters support candidate x.” The premises of the argument come from the raw polling data. Implied in the stated result is that the organization that polled the voters gathered results similar to the following: Voter 1 expressed support for candidate x. Voter 2 expressed support for candidate x. Voter 3 expressed support for candidate y. Voter 4 is undecided. The polling organization presumably contacted more than just four voters, but however many they contacted, their results (in this example) show that half express support for candidate x. These data serve as the premises for the conclusion “50 percent of all voters support candidate x.” As with all inductive arguments, however, we can’t be sure that the conclusion is true. The polling company surveyed a relatively small number of voters and then assumed the population at large would express support for candidates in similar proportions to those actually surveyed. So the data is presented as evidence supporting the conclusion, but the conclusion is far from certain. In looking at these two examples of inductive arguments (the horse argument and the polling data argument), we can see another feature of inductive arguments: they can be made stronger by adding more evidence. Think back again to deductive arguments for a moment. Remember that deductive arguments are all-or-nothing: all the information in the conclusion is already expressed in the premises, so if the premises are true, then we are 100 percent certain that the conclusion is true. In that sense, deductive arguments cannot have varying degrees of strength or weakness. But inductive arguments can, and one of the most obvious ways to improve the strength of an inductive argument is to increase the number of premises that provide evidence supporting the conclusion. In the example argument about horses having four legs, our argument becomes stronger if we count the legs on more horses. Likewise, we can be more confident in the accuracy of the political poll if the polling organization samples a larger number of voters. The polling argument can also be strengthened in other ways: sampling voters from diverse geographical regions, contacting voters at different times of the day (normal work hours during the week, and also evenings and weekends, for example), using different methods to contact voters (landlines and cell phones, for example), and so on. All of these methods would make a stronger case for a conclusion that intends to say something about “all voters.” Now that we have described the basic features of inductive argumentation, we should note one common misunderstanding about inductive arguments. Sometimes inductive reasoning is described as reasoning “from particulars to a universal.” To reason inductively, it is said, we examine the similarity of particular
items, and then from this similarity we are able to arrive at a universal principle. Here is an example: Plato was a man, and he was mortal. Socrates was a man, and he was mortal. Aristophanes was a man, and he was mortal. Every other man that I know about is mortal. Therefore, all men are mortal. Notice, first, that this fits the description of inductive reasoning quite well: an accumulation of evidence points to a conclusion; the conclusion is only probable, not certain; and the conclusion contains information that is not explicit in the premises. Second, it does indeed seem to be reasoning from particulars to universals. If all individual men observed are mortal, then we could safely conclude that all men are mortal. The particular item is the mortality of the individual men, and the universal principle is the claim that all men are mortal. The same could be said of both the horse argument and the polling data argument above. But inductive reasoning doesn’t always go from particulars to universals. Here is an example: All dogs are mortal. All cats are mortal. All bears are mortal. Etc. Therefore, this creature is also probably mortal, even though I have no idea what kind of creature this is. Here again, this example fits nicely with the description of inductive reasoning. It is based on the accumulation of evidence that leads to a probable (but not certain) conclusion, and the conclusion contains new information that is not stated in the premises. But this argument does not go from particulars to universals. In fact, it goes the other way: it begins with several universal principles and concludes with a particular individual fact. So while you may hear people say that inductive reasoning draws universal principles from particular observations, keep in mind that this is not always the case. Laws of Logic In a chapter dealing with the basics of reasoning, it is worth mentioning a little more about logic. For those who have not had formal training in the subject, logic can seem to be somewhat mysterious and perhaps esoteric. But in truth, logic is one of the most practical branches of philosophy. Logic is the study of good reasoning, and it is likely that you already grasp basics of logic just through your own common sense and innate reasoning abilities. As we think about good reasoning and good arguments, the most basic and fundamental principles of logic are often summed up in what are called the three laws of logic or sometimes the three laws of thought: identity, noncontradiction, and the excluded middle. These three laws should probably be called principles of common-sense reasoning because they appeal to basic principles of reasoning that just about everyone is aware of. Most people might not think about, study, and analyze these principles quite like philosophers do, so a brief examination of them can help us see that they are part of the very fabric of what we call common sense. The three principles of common-sense reasoning are the law of identity, the law of noncontradiction, and the law of the excluded middle. The Law of Identity The law of identity says that whatever something is, that is what it is. Simple, right? The law of identity is so basic that almost everyone is able to grasp it on the first try. Logicians will sometimes describe the law of identity by using a letter of the alphabet like this: A is A. That means for any object (A), that object is what it is (A) and not something else. This is just a formal way of pointing out what should be fairly obvious: things are what they are. We can describe it another way. In addition to saying that things are what they are, we can also say that things exist in particular ways. Think about the book you are reading right now (assuming you aren’t reading a digital copy): the book has a particular size and shape, it has a particular number of pages with particular words on them, and the cover has a particular design. Maybe it has a mark on this page from your pencil or pen, and perhaps a page or two has been folded over at the corner. The point is that to understand what the book is (the one you are holding in your hands), you can observe all the particulars of what it is like. If the book wasn’t exactly like that in every way, then it wouldn’t be that book. It would be something else (perhaps a different book, or something else altogether). And this doesn’t just apply to books; it also applies to everything else: horses, trees, my sister’s cat, my love for my mother, or your hopes for the future. Each of these things exists in a
particular way, and all of the particulars about the way something exists describe that thing’s identity. The law of identity says that A is A. Sometimes those who criticize the law of identity will do so by suggesting that it is nothing more than an empty exercise in repetition—as the song from the old TV show says, “A horse is a horse, of course, of course.” But that isn’t quite what the law of identity is doing. It isn’t just repeating “a horse is a horse” or “a book is a book.” Instead, the idea here is to point to the particular ways in which a particular thing exists. So when this principle is described by saying “A is A,” the first A stands for the object or item in question (like “this particular book”), and the second A stands for the particular ways in which that particular book exists. This, after all, is how we know what something is. If it weren’t for the law of identity, we wouldn’t be able to pick out objects or ideas and differentiate them from other objects and ideas. If the law of identity didn’t apply, and things didn’t exist in particular ways, then a meaningful understanding of the world around us would be impossible. The law of identity should be obvious to everyone. It is common sense; almost everyone grasps intuitively the principle that things are what they are. When we make arguments, however, we can occasionally make mistakes regarding identity. It is hard, after all, to make a good argument about what “the church fathers believed,” for example, if we aren’t sure who we are talking about or in what century they lived. Bad arguments may contain confusions of identity, but good arguments always clearly identify things as they are. The Law of Noncontradiction Closely related to the law of identity (and just as important for meaningful understanding of the world) is the law of noncontradiction. (In some contexts this principle is called the law of contradiction, which could be confusing.) Like the law of identity, the law of noncontradiction also points to the particular ways things exist—their color, size, or shape, for example. These are called properties. Something that is blue, for example, has the property of being blue. The law of noncontradiction says that an object that has the property being blue cannot at the same time and in the same sense also have the property not being blue. Just as with the law of identity, logicians sometimes use letters of the alphabet to express the law of noncontradiction: For any object x and any property F, x cannot be both F and not-F at the same time and in the same sense. God cannot be both omnipotent and not omnipotent. A ball cannot be both blue and not blue. A common attempt to deny the law of noncontradiction is to cite examples that seem to violate the principle but also seem to be true. Consider, for example, a ball that is half blue and half white. Someone might say, “This ball is both blue and not blue at the same time.” The solution here is just a matter of precision. To be more precise, it is not true that the ball is both blue and not blue. The truth is that half of the ball is blue and the other half of the ball is not blue. Someone else might cite Charles Dickens’s famous opening line of the book A Tale of Two Cities: “It was the best of times, it was the worst of times.” Recall that the law of noncontradiction asserts that any object cannot be both F and not-F at the same time and in the same sense. Dickens isn’t contradicting himself because he means that it was the best of times in one sense and the worst of times in an entirely different sense. No matter what other kinds of examples like this are suggested, the solution is simple: be more precise in describing the properties, and you will see that the law of noncontradiction always applies. Another way to think about the law of noncontradiction is that for any proposition P, P and not-P cannot both be true at the same time and in the same sense. Framed in this way, we see that P and not-P are contradictory propositions. The law of noncontradiction applied to this tells us that these two contradictories cannot both be true. The law of noncontradiction can be a very helpful tool in evaluating arguments. A contradiction in an argument always tells us that the argument is bad. As soon as we spot a contradiction in an argument, we can be sure that either (a) the conclusion is false or (b) the reasons provided cannot possibly support the conclusion. Good arguments, however, do not contain contradictions, and they do not fall prey to the naive objections that
are sometimes offered against the law of noncontradiction. The Law of the Excluded Middle Like the law of noncontradiction and the law of identity, the law of the excluded middle is a common-sense aspect of making good arguments. This principle follows from exactly the same common sense that helps us understand the law of noncontradiction. The law of noncontradiction asserts that P and not-P cannot both be true at the same time and in the same sense. The law of the excluded middle says that either P or not-P must be true. That is, for any proposition, either the proposition is true or its negation is true. This principle is called the excluded middle because it recognizes the common-sense idea that there is no middle ground between a proposition and its denial. There simply isn’t anything between P and not-P. If we say, for example, that P is “God exists,” the law of the excluded middle says that either “God exists” is true or its negation, “God does not exist,” is true. There just are no other options between those two. Implied by the law of the excluded middle (but not saying exactly the same thing) is the principle of bivalence. While the law of the excluded middle says that for any proposition P, either P or not-P is true, the principle of bivalence says that for any clear, unambiguous statement, that statement is either true or it is false. While this is not without controversy among logicians, it seems fairly obvious that a clear, unambiguous statement, such as “the earth is flat,” must be either true or false. There is no middle ground between the two options. So if P is “the earth is flat,” the law of the excluded middle says that either P or not-P must be true—either “the earth is flat” is true or “it is not the case that the earth is flat” is true. Bivalence, on the other hand, says that the statement “the earth is flat” is either true or false. The distinction here may seem subtle, and indeed some logicians deny that there is a difference. One reason for the controversy is that some logicians think that for some stated propositions the law of the excluded middle applies but the principle of bivalence does not. We will leave it to you to further explore this controversy if you wish to better grasp the difference between the principle of bivalence and the law of the excluded middle. For our purposes, however, it will suffice to say that the principle expressed as the law of the excluded middle is (like the others) a matter of common sense. Some may object to this principle on the grounds that many statements are ambiguous or have indeterminate meaning. Imagine this claim about our philosopher friend Socrates: “Socrates was bald.” Those who object to the law of the excluded middle might point out that the top of Socrates’s head was indeed bare, but he did have some hair on his head. So if P is “Socrates was bald,” it seems we have a case with some middle ground: neither P nor not-P are true. It is not quite true that “Socrates was bald,” nor is it true that “Socrates was not bald.” This is a confusion of what it means to be bald, however, and not an example in which the principle of the excluded middle does not apply. If a precise definition is given about what it means to say that someone is “bald,” the confusion disappears. If “bald” means “has no hair whatsoever on the scalp,” then it is easy to see that either Socrates was bald or Socrates was not bald. Things are a certain way, or they are not. There is no middle ground between the two options. Good arguments therefore present clear statements that don’t contain the kind of confusion that arises from ambiguity. Instead, good arguments contain statements that are either true or false. Conclusion In the section above we discussed the three laws of logic. By referring to these principles of reasoning as “laws,” we are not suggesting that they are like rules enforced externally—like traffic laws are in place to make sure everyone drives safely and according to the same conventions. Instead, to say that the basic principles of logic are “laws” is more like when we talk about physical laws, such as the law of gravity or the law of conservation of mass. These physical laws are merely descriptions of the way the world works and are useful at predicting the way physical objects in the universe behave. This is also the case for the laws of logic—in the sense that they aren’t merely conventions of behavior, they can’t be abolished by a majority vote, and they don’t depend on culture or religion. The laws of logic just tell us how good
reasoning works, and they are universally applicable across all times and all cultures. 3 Fallacies In chapter 1 we mentioned the common misunderstanding people have about what a fallacy is, and what it means to say that something is fallacious. In our culture, people commonly use the word fallacy when they really mean to say that something is false. If a person believes that the conclusion of an argument is false, that person will often say that the argument is fallacious. This represents an incorrect understanding of what a fallacy is and of what it means to say that an argument is fallacious. Contrary to the popular misunderstanding, a fallacy is simply a mistake or defect in reasoning, and a fallacious argument is one that makes a mistake or contains some kind of defect in its reasoning. When such a mistake is made, the premises of the argument (whether they are true or false) do not actually provide good reasons to think the conclusion is true (whether it really is true or not). We hope it is clear to you by this point that if you want to make good arguments, you must avoid fallacies. If you are interested in persuading someone that your position is true, or that they should adopt a new belief or take a particular course of action, the arguments that you present can only be effective if you avoid mistakes in reasoning. If you are interested in supporting your conclusions through good arguments, then you must remember that reasons offered in a fallacious argument are no reasons at all. So you need to learn how to avoid fallacies as you construct arguments—and if you inadvertently make such a mistake in reasoning, you need to know how to correct it. Additionally, if you want to evaluate arguments offered by others, you must be able to spot any fallacies so that you can think clearly about the ideas being presented and evaluate more carefully whether you should accept the conclusions of those arguments. Therefore, being able to identify and avoid fallacies is essential for critical thinking and for making good arguments. In this chapter we present several common fallacies so that you will learn how to spot them and how to avoid them. There are two kinds of fallacies: formal and informal. Formal fallacies are those that make mistakes in how the argument is structured. These are called formal because the defect is in the form of the argument. Informal fallacies, on the other hand, are not related to the form or structure of the argument but rather to the content or the meaning of words and phrases in the argument itself. Formal Fallacies In the last chapter, we introduced two common valid forms of deductive syllogisms: modus ponens (MP) and modus tollens (MT). Any argument that takes one of these forms is formally valid, no matter what the premises and conclusion are. Recall the modified example argument about Socrates we have been using throughout this book. It takes this form: If Socrates is a man, he is mortal. Socrates is a man. Therefore, Socrates is mortal. Because this argument takes the form of MP, it is a formally valid argument. Also in the last chapter, we offered an example argument for God’s existence based on the existence of objective moral values. This argument took the form of MT; therefore, it is formally valid. There are many other valid forms of syllogistic arguments besides MP and MT, and if you take a course in logic, you will probably be exposed to many of them and learn the basics of how to recognize them. Just as there are many valid forms of syllogistic arguments, there are many formal fallacies. Here we want to mention just two. In both cases, these arguments will appear to be valid syllogisms at first glance, but through careful analysis we can see that they are formally invalid. Affirming the Consequent An if … then statement, like the ones that appear as the first premise in MP and MT, is called a hypothetical proposition. In other words, any statement that takes the form “if A, then B” is a hypothetical proposition. The first half of any such proposition is the antecedent, and the second half is the consequent. So for the statement “if A, then B,” A is the antecedent and B is the consequent. In the example “If Socrates is a man, then he is mortal,” the antecedent is “Socrates is a man,” and the consequent is “he is mortal.” In every such hypothetical proposition that takes the form “if A, then B,” what is being said is that if A is true, then B is guaranteed to be true. Recall that MP gets its name from a
term that means “mode of affirming.” It gets this name because it affirms the antecedent in order to show that the consequent must be true. We start with the hypothetical proposition (if A, then B), and then we affirm A; and since A guarantees B, then B must be true as well. That line of reasoning is perfectly valid. But sometimes in the course of using these kinds of hypotheticals to prove conclusions, we commit the fallacy called affirming the consequent. To the untrained eye, this fallacious form has the appearance of MP, but it isn’t MP. Instead, it takes a different form that contains a serious defect in reasoning. The form of this fallacy is as follows: If A, then B. B. Therefore, A. This fallacy is so named because it affirms the consequent (B) of the hypothetical proposition in an attempt to prove the conclusion (A). Here are a couple of example arguments that take this fallacious form: If Jesus is God, he can turn water into wine. Jesus can turn water into wine. Therefore, Jesus is God. If God inspired the Bible, then the Bible is true and trustworthy. The Bible is true and trustworthy. Therefore, God inspired the Bible. Depending on your beliefs about Jesus, God, and the Bible, you might believe that the premises and conclusion of both arguments are true. Even if all of these statements are true (and we happen to think that they are), these two arguments contain a critical defect in reasoning: they commit the fallacy of affirming the consequent. In each case, they begin with a hypothetical proposition (if A, then B), but instead of affirming the antecedent (A) in order to prove the truth of the consequent (B), they attempt to prove the truth of the antecedent by affirming the consequent. To see the problem more clearly, let’s look at a simple example of this fallacy: If it is raining, the sidewalk is wet. The sidewalk is wet. Therefore, it is raining. In this example we can immediately see what is wrong: the sidewalk could have become wet from any number of causes other than rain. Perhaps someone turned on the garden hose and aimed it at the sidewalk. Maybe a large chunk of ice was placed on the sidewalk and melted in the heat of the sun. The problem is this: just because rain guarantees that the sidewalk will be wet, it doesn’t mean that the sidewalk being wet guarantees that it is raining. Said the other way around, you can’t properly conclude that it is raining just because the sidewalk is wet—and the reason for this is that the sidewalk could have become wet from many other causes right in the middle of a bright, sunshine-filled, rain-free day! Remember, though, that the fallacy has nothing to do with whether the statements are true. Instead, the fallacy is in the form. It could indeed be raining, and that could be the reason that the sidewalk is wet. The form is fallacious, however, because affirming the consequent cannot possibly guarantee the truth of the antecedent, as it purports to do. It would be a deductive argument with true premises and a false conclusion—something you can never have because true premises of a deductive argument guarantee the truth of the conclusion. Again, you can prove that the sidewalk is wet by affirming the fact that it is raining, but you can’t prove that it is raining by affirming that the sidewalk is wet. Now that we have analyzed this simple example, glance back up to the argument about Jesus turning water into wine. You’ll notice that the argument attempts to prove the antecedent by affirming the consequent. But just as in the rain/sidewalk example, any number of other facts about Jesus could explain his ability to turn water into wine. He could have been a sorcerer, specializing in the conversion of water to other types of beverages. He could have been a mere mortal endowed by God with special powers to turn water into wine. Or he could in fact be God. The trouble is that you cannot prove that Jesus is God simply by affirming the consequent of the hypothetical—that he can turn water into wine. The same is true for the example about God inspiring the Bible. Just because something is true and trustworthy does not mean it is God inspired. Of course, in any of these examples you could properly prove the consequent by affirming the antecedent. But to attempt to prove the antecedent by affirming the consequent is formally fallacious. Denying the Antecedent Recall that MT presents a hypothetical statement (if A, then B) and then denies the consequent (B) in order to prove
that the antecedent (A) is not true. Let’s say that a different way: The hypothetical means that if A is true, then B is guaranteed to be true. MT denies B. But since A guarantees B, denying B proves that A must be denied as well. Just as with MP, an attempt to construct an argument of the form MT can go wrong, and a defect in reasoning can be introduced. The fallacy of denying the antecedent takes the following form, similar to MT, but formally invalid: If A, then B. Not A. Therefore, not B. This fallacy makes the mistake of denying the antecedent in an attempt to prove that the consequent must be denied. Here is an example argument that takes this fallacious form: If God does not exist (A), then Christianity is false (B). God does exist (not A). Therefore, Christianity is true (not B). When we attempt to put this into “if A, then B,” we see that A is “God does not exist,” and B is “Christianity is false.” So “not A” means “God does exist,” and “not B” means “Christianity is true (i.e., not false).” Here again, you may believe (as we do) that the premises and the conclusion of this argument are true. But the argument is clearly fallacious for this reason: while a denial of the consequent requires a denial of the antecedent (because the antecedent guarantees the consequent), a denial of the antecedent does not require a denial of the consequent. We know this can seem complicated the first time you read it, so let’s go back to thinking of rainy weather and wet sidewalks to see more clearly what is wrong here: If it is raining, then the sidewalk is wet. It is not raining. Therefore, the sidewalk is not wet. Do you see what is wrong? The sidewalk could indeed be wet, even if it is not raining. (Remember the garden hose and the chunk of ice?) Likewise with the earlier example: it could be the case that Christianity is false, even if God does exist. God’s existence alone does not guarantee that Christianity is true. Before we move on to informal fallacies, it is worth acknowledging that all the above material may have seemed confusing to you, especially if this is the first time you have read about these things. If so, you might need to review the above material several more times to make sure you understand the defect in reasoning in each of the two fallacies mentioned. It is quite possible that a person who has never heard of these fallacies can still spot the mistakes in reasoning, all the while not having any idea what they are called. In presenting this material, our primary goal is not to equip you to name the fallacies (“Aha! I have spotted an example of the fallacy of affirming the consequent!”). Rather, our goal is to help equip you to spot the actual mistake in reasoning (“Wait a minute! There are many possible causes for the sidewalk being wet. Just because it is wet doesn’t mean it must be raining!”). Of course we can’t fully equip you to do that for every possible mistake in reasoning, especially in such a short book as this. But we hope that the discussion of formal fallacies helps contribute to the process. The same is true as we discuss informal fallacies below. Being able to name the fallacies is good, but being able to identify the root of the mistake in reasoning and being able to avoid such mistakes in your own arguments are much more important. Informal Fallacies While formal fallacies make their mistakes in the form of the argument, informal fallacies make their mistakes in the content and the meaning of the content. A careful eye will see examples of formal fallacies in a wide variety of contexts, but many, if not most, of the fallacies we find will be informal. The reason for this, perhaps, is that informal fallacies are often very tempting to commit. They tend to lure us in, tempting us with an all-too-easy way to prove a conclusion that we so desperately want to prove. In the end, however, they are fatally defective and unable to help us accomplish our goals. For this reason we must learn to see them for what they are and to avoid them in our own arguments. While countless informal fallacies can be committed, we will mention just a few of the more common ones that you are likely to encounter (in your own thinking or in the arguments of others). Begging the Question The fallacy of begging the question, also referred to by the Latin term petitio principii, is an example of circular reasoning. Reasoning in a circle means that you create an argument in which the truth of one or more premises depends on the truth of the conclusion. In other words, this fallacy makes the mistake of
assuming in a premise what the argument itself is supposed to be proving. The following dialogue is commonly given as an example of this kind of mistake in reasoning: Sam: God exists. Joe: Why should I believe that? Sam: Because the Bible tells us that he does. Joe: Why should I believe the Bible tells the truth? Sam: Because the Bible is God’s Word, and God cannot lie. This is fallacious, and an example of circular reasoning, because the truth of the last two premises “the Bible is God’s Word” and “God cannot lie” both depend on the conclusion being true (“God exists”). Here is another example: “I know that God exists because of the many wonderful blessings he has given me.” This is circular because God can only give blessings if he exists. One more example: It is impossible that God exists. We know this conclusively because the entire universe is composed of physical matter. While it is possible that somewhere in the unexplored physical universe there may be a very great and powerful being, those who believe in God claim that he is an immaterial, spiritual being. But because only physical, material things exist, we can conclude that it is not just unlikely that God exists—it is impossible. This is the kind of thing that a scientific naturalist might say. While this example is a bit more subtle than the others, it is still circular: to prove the conclusion that God (an immaterial, spiritual being) cannot exist, the one proposing this argument first assumes that only physical, material things exist. Unfortunately, circular reasoning is quite common because it is very tempting (as we suggest above). If we stop and consider the psychology behind this kind of argument, we can probably (sympathetically) see what is going on. Long before Sam attempts to construct an argument to prove to Joe that God exists, Sam already believes that God exists. The belief in the truth of the conclusion comes before the argument is ever offered. Since Sam already believes that God exists, the argument he constructs seems to be quite reasonable. Without giving it much thought, Sam takes it for granted that God exists because he is already convinced that God exists—so it doesn’t seem inappropriate at all to construct premises in an argument that take for granted that God exists. The same is true for our scientific naturalist friend: before he attempts to construct the argument, he already believes that nonphysical beings cannot possibly exist. So of course it doesn’t seem to him that he is making a mistake in reasoning when he offers an argument that depends on the conclusion being true. Avoiding this fallacy in our own arguments is a simple matter of critical self-reflection. If we learn to honestly assess what we believe as we develop arguments to support these beliefs, we will be less likely to inadvertently engage in circular reasoning. Any time we do argue in a circle, we are not really giving any good reasons to support the conclusion. Ad Hominem The ad hominem fallacy is committed when an argument is directed at a person, instead of at a line of reasoning, in an effort to show that the opponent’s conclusion or conclusions are incorrect. The name of this fallacy comes to us from Latin and means “to the man.” This fallacy is a kind of personal attack; but since personal attacks are (unfortunately) common in our culture, we must note that not all personal attacks are fallacious. Here is an example of the ad hominem fallacy: Raising the minimum wage is good for our economy. Of course the powerful CEO of the major corporation would say that raising the minimum wage is bad for the economy because he is motivated by nothing more than greed and pure profit! The reason this is fallacious is that the motivations of the CEO are irrelevant to determining the question of whether raising the minimum wage is good for the economy. The person making this argument is simply attacking the motives of the CEO, without providing any relevant reasons to help us determine whether the conclusion is true or false. Even if the CEO is motivated by greed and profit, that fact has nothing to do with whether raising the minimum wage is good for the economy. The CEO may be able to present good arguments supporting the claim that raising the minimum wage would harm the economy. So to avoid the ad hominem fallacy, his opponent would need to go after the premises and reasoning within that argument rather than attacking the motives of the CEO. It can be tempting to
commit this fallacy, especially if we really do think that our opponent is of questionable character or has impure motives, and especially if we really do think that the claim the person is offering is false. If we want to make good arguments, however, we must examine our own line of reasoning carefully to make sure that we are not appealing to irrelevant motivations on the part of our opponent in our attempt to prove that our opponent’s claim is false. As we have already suggested, not all personal attacks are fallacious. There are at least two circumstances in which it would not be fallacious to attack the character or motives of a person: when the character or motives of the person are relevant, or when the attack is not offered as a reason to reject a claim. First, a situation could arise in which a person’s character or motives are relevant to the question under consideration. An example of this would be a court case in which a witness was called to give a testimony. It is not fallacious for opposing counsel to attack the character or motives of the witness in those cases in which the court is relying on the character and motives of the witness as evidence that the testimony is true. Second, it would also not be fallacious to simply make a personal attack against someone without using that attack to suggest that a conclusion is false. If you are in a public debate against an opponent, it would not be fallacious for you to begin your opening statement by attacking the character and motives of your opponent as long as you are not offering your attack as a reason that your audience should reject your opponent’s conclusion. Perhaps such a move would be impolite, but it would not be an example of fallacious reasoning. Ad Populum Like the ad hominem fallacy, the ad populum fallacy is fallacious because it asserts something that is irrelevant to the argument. It gets its name from Latin, meaning “to the people,” and is an appeal to the popularity of a claim in an attempt to show that the claim is true: since so many people believe the claim, the claim must be true. This fallacy is often committed in the context of religious claims: “So many people, in so many places and across the ages, have believed in God. God must exist!” This is clearly fallacious, because the number of people who believe the claim that God exists is irrelevant to the truth of the claim. Here are a few other examples: • Because so many people oppose a tax increase, that policy must be bad for the country. • The president was elected by an overwhelming majority; therefore, he must be the right man for the job. • Nine out of ten dentists recommend this brand of chewing gum, so chewing it must not have any negative effects on dental health. • Almost all Christians throughout the last two thousand years have believed that Jesus is God, so it must be true. In each of these examples, you can see that the appeal made “to the people” is not relevant to whether the claim is true or false. Because these appeals are not relevant to the claim, they are examples of fallacious reasoning. It must be noted, however, that not all appeals to popularity are fallacious. For example, if the claim is “Candidate A will win the election,” then appealing to the fact that a majority of respondents in the poll said that they were going to vote for candidate A is relevant; so appealing to the people in this sense is not fallacious. Making these kinds of appeals is also appropriate in sociological studies. Sociologists often focus on describing what is true of groups of people or cultures, and in the process of doing that, it is perfectly appropriate to appeal to what is true about “most people” in that group or culture. It is always fallacious, however, when we appeal to the popularity of a belief or claim in our efforts to show that the claim is true. Inappropriate Appeal to Authority Sometimes appeals are made to an authority figure: because an expert thinks that the claim is true, the claim must be true. In some cases this can be perfectly appropriate; relying on expert opinion can be a reliable way to determine whether certain claims are true or false. In many cases, however, the fact that the person is an authority figure is irrelevant to the claim under consideration. In such cases the appeal to authority is inappropriate and fallacious. One of the most common contexts for this fallacy to occur is in advertisements: a famous person tells us that a product is good, and that person’s testimony is presented as a reason to think that
the product is good. This is fallacious when the person’s fame is irrelevant to the question of whether the product is any good, such as when a famous athlete promotes a specific brand of razors, clothing, or pizza. This fallacy also arises when Hollywood stars are called to testify before Congress about an issue outside their area of expertise. These kinds of appeals are fallacious because they assert (sometimes implicitly, sometimes explicitly) that the person’s fame is a good reason to accept their claim as being true. Though it is fallacious to appeal to an authority figure for matters that lie outside that person’s area of expertise, in some cases it can be quite tempting to do this. In debates about God’s existence, for example, a theistic scholar is often paired with an atheistic scientist. In the aftermath of these debates, the audience can be tempted to appeal to the authority or expertise of one or the other debate participants. While the scientist, for example, may be an expert in her particular field of science, that expertise does not extend to other fields, such as philosophy or theology. Likewise, the theist may be a well-recognized expert in the philosophy of religion, but his expertise may not extend to scientific matters. Richard Dawkins (an atheist who is a recognized expert in zoology and evolutionary biology) is no more qualified to evaluate the philosophical arguments for God’s existence than any other nonexpert. Likewise, William Lane Craig (a theist who is a recognized expert in philosophy) is no more qualified to evaluate some established principle in the field of genetics than any other nonexpert. While each of these men enjoys expertise in his field, it would be fallacious for someone to appeal to that authority to defend the truth of a claim that lies outside that field of expertise. Genetic Fallacy The genetic fallacy, sometimes called the fallacy of origins, is an attempt to prove false (or true) an idea based on the source of that idea. We commonly see this fallacy arise in debates about God’s existence or about the truth of some particular religious viewpoint. Atheists, for example, will often point out that people raised in predominantly Christian cultures will come to believe that Christianity is true, while people raised in Muslim countries will come to believe that Islam is true. The claim is then made that Christianity (or Islam) must be false because it can be shown that people believe in a particular religion only because that is what they were taught to believe. This line of reasoning is clearly fallacious, however. How a person came to believe that Christianity is true is irrelevant to the question of whether Christianity is actually true. Of course this kind of fallacious reasoning can go both ways: Christianity is true because that is what my parents taught me. Here again, the origin of the belief doesn’t help us determine whether the belief is actually true. False Dilemma Sometimes referred to as black-and-white thinking, the false dilemma is a fallacious line of reasoning that inappropriately suggests that a question has only two possible answers and that a choice must be made between those two, when in actuality more than two possible answers are available. For example, someone might say, “If you don’t support prayer in public school, you must be an atheist.” This is fallacious because it falsely suggests that there are only two options for any of us: either I support prayer in public school or I’m an atheist. But clearly these are not the only two choices: a theist may oppose prayer in public school, and (perhaps) an atheist could support it. This fallacy also occurs in some areas of controversy in which two positions in the controversy are habitually emphasized to the exclusion of other options. For example, in Christian theology it might be said, “You are either a Calvinist or an Arminian.” In politics, people sometimes act as if you are either a Republican or a Democrat. In each of these examples, a highly controversial issue (or set of issues) has resulted in the polarization of opponents into one of two major camps that tend to dominate the debate. To present these as if they were the only options available is fallacious. It is important to note that not all dilemmas are false, so presenting a dilemma is not always fallacious. It is a true dilemma to say, “You are either a Calvinist or not a Calvinist,” for example, or, “You are either a Republican or not a Republican.” In these examples, the principle of bivalence is brought to bear: for any statement, it is
either true or false. In other cases, only two options are available: “If you are going to make a turn, you must turn either to the right or to the left.” So we see that a dilemma is only false, and therefore an element in faulty reasoning, if more than two options are available. Straw Man Muhammad Ali is widely recognized as the greatest boxer of his time and one of the greatest heavyweight boxers who ever entered the ring. Which would be an easier task for you to achieve: surviving a twelve-round bout against Muhammad Ali … or surviving a twelve-round bout against a life-sized inflatable doll that looks like Muhammad Ali? The difference between those feats helps us to understand what the straw man fallacy is. The straw man fallacy is one in which you create an intentionally weakened, distorted, or obviously false version of your opponent’s argument, and then attack that version specifically because it is easier for you to defeat than the real thing. You know you can’t defeat Muhammad Ali, so you put up the life-sized inflatable in Muhammad Ali’s place and then punch away. This fallacy is so named because, similar to an inflatable doll, it has in mind Muhammad Ali’s clothes stuffed with straw rather than Muhammad Ali himself. This strategy is fallacious because it misrepresents your opponent’s argument in an effort to prove that your opponent’s claim is false. To correct this fallacy, you need to address your opponent’s actual argument, because that is what your opponent is using to support the claim. Red Herring The red herring fallacy is an intentional distraction away from relevant issues. The name comes from a kind of fish (usually a herring, we suppose) that was strongly cured or smoked so that it emits an unpleasant, powerful aroma (that is, it stinks). If you are thinking or talking about something important, it is easy to be distracted if someone starts waving a smelly fish around. This fallacy occurs any time a person introduces a new concept that is not immediately relevant to the argument or claim under consideration for the purpose of distracting the audience or shifting the discussion away from an undesired result. For example, if the question under consideration is whether abortion is immoral, it would be a red herring to say, “I don’t think abortion is immoral; and anyway, we have a problem with overpopulation as it is. What we really should be concerned about is proper distribution of resources to eliminate poverty.” Here, a new idea is introduced (distribution of resources to eliminate poverty) specifically as a distraction designed to divert attention from the actual question (whether abortion is immoral). While it may be tempting to insert such distractions into a debate, it is always fallacious to do so. Conclusion Each of the fallacies above has a common element that makes the reasoning fallacious: they present reasons we should accept a claim as true, but these reasons turn out not to be good reasons at all. In most cases the reasons don’t give us anything by which we can begin to determine whether the claim is true or false. This is what it means for an argument to be fallacious: the premises (reasons given) do not have the proper connection to the conclusion (the claim). As you strive to learn how to craft good arguments, it is necessary to make note of the more common and tempting ways in which our reasoning can go wrong. To make good arguments, you must avoid fallacies. While we have described some of the most common fallacies in this chapter, we could have named many more, and we encourage you to continue your study of common fallacies in arguments. The more fallacies you are aware of, the more likely it is you will avoid them in your thinking and in your arguments.Richard A. Holland Jr. and Benjamin K. Forrest, Good Arguments: Making Your Case in Writing and Public Speaking(Grand Rapids, MI: Baker Academic: A Division of Baker Publishing Group, 2017), 1–46.Five A Little Logic I have always been somewhat envious of auto mechanics. Like many newly married couples, my wife and I struggled financially in the early years of our marriage. Our first cars were clunkers and needed constant maintenance. We could never afford to take them to a skilled mechanic.
Many Saturday afternoons you would find me lying in the driveway underneath one of our cars changing the oil or attempting to put in a new set of brakes. I envied those auto mechanics for their skills and for their garages with hydraulic lifts. But mostly I envied them for their tools. You can understand what I mean if you have ever tried to work on a car with just a screwdriver and pair of pliers. How often I wished for a first-class ratchet set along with an air-powered driver. With the right tools even the most difficult job can be performed with relative ease. In the hands of a skilled mechanic, the right tools can produce a work of art. Every field employs certain tools to accomplish the necessary tasks in that field. The skillful use of these tools will often determine one’s effectiveness in operating in that field. Auto mechanics use wrenches and ratchets. Surgeons use scalpels and souchers. Carpenters use hammers and saws. Philosophers use logic. The first task in being an effective philosopher, then, is to learn how to use the tools of philosophy, and that means becoming a skillful logician. Therefore, the second half of this book will introduce you to logic and argumentation. We begin with a discussion of the foundation for logical reasoning. The Laws of Logic At the foundation for all reasoning are the laws of logic, often referred to as the first principles of logic. The laws of logic make discourse possible. If they are not recognized as true, then nothing we claim makes any sense. Therefore, it is important to have a firm grasp of these laws. There are traditionally three laws of logic. The first and perhaps most primary law is the law of noncontradiction, which states: Something cannot both be and not be at the same time and in the same respect. The law of noncontradiction can be expressed symbolically: ~ (P • ~P). The ~ means “not” or “non” and negates any term or proposition that follows it. The parenthesis means “both.” The • means “and.” The letter P is called a variable, and it can refer to any term or proposition. Therefore the logical formula reads, “It is not the case that there can be both P and non-P.” Stating it this way clears up some confusion concerning the law of noncontradiction. A student once asked, “But it seems to be saying that everything is either black or white. Aren’t things sometimes gray?” The formula clears up this confusion. The logical opposite of black is not white but is nonblack, which would include any color, including gray. There is never an exception to this law. The medieval philosopher Avicenna, tired of the intellectual games of sophists, wrote, “Anyone who denies the law of non-contradiction should be beaten and burned until he admits that to be beaten is not the same as not to be beaten, and to be burned is not the same as not to be burned.” Contradictions cannot be. In spite of the foundational aspect of this law, I often encounter persons who think they can prove contradictions are possible. A student once stood up in class and walked over to the open door of the room. He stood on the threshold, placed one foot in the classroom and one in the hallway and claimed that he was both inside the room and outside the room at the same time. Hence the law was not true—or so he claimed. However, this student was neglecting an important element of the law: Something cannot both be and not be at the same time and in the same respect. He had placed part of his body in the room and part out of the room at the same time. I challenged him to place his entire body both inside the room and outside the room at the same time. He quietly slunk back into his seat. Some Christians have challenged this law by claiming that God is omnipotent (all-powerful) and therefore can do anything, including contradictions. They will often quote Matthew 19:26, where Jesus says, “With people this is impossible, but with God all things are possible,” as proof of their claim. There are a couple of problems with this reasoning. First, the context of this passage is salvation. Jesus is speaking of how difficult it is for a rich person to be saved because he often clings to his riches instead of trusting God. Jesus uses two hyperboles to make his point. The first is that of a camel going through the eye of a needle, and the second is “with God all things are possible.” These are both hyperbolic statements. He no more means “all things” to be taken absolutely and universally than he does a real camel going through an eye of a
needle. His point is that none of us can save ourselves; only God can save us. Second, when he says “all things are possible with God” he means “all things that can possibly be are possible with God.” There are some things that cannot possibly be: contradictions. For example, God cannot both exist and not exist at the same time and in the same respect. He cannot be God and also not be God. That is a contradiction, and contradictions are impossible. This has nothing to do with omnipotence. There are some things that, by their nature, are not possible. A triangle with only two angles cannot be because it would no longer be a tri-angle. A married bachelor is impossible because he would be a married-unmarried person, and that makes no sense. Even God cannot create such things, not because he does not have the power but because such things cannot be. The second law of logic is the law of excluded middle, which states: Something either is or is not, or P v ~P. The v in this formula, called a wedge, means “either/or.” So the formula reads, “Either P or non-P.” It is called the law of excluded middle because it excludes the possibility of something in the middle of existence and nonexistence. A thing either exists or it does not; there is no tertian quid (“third what”). There is no such thing as something half-existing and half not-existing because the part that is half not-existing would have to exist as a nonexisting part of the thing, and that makes no sense. The third law of logic is called the law of identity, which states: Something is what it is. Stated as a formula, it reads, “P = P.” This may be the most obvious law, as it claims that whatever a particular thing is, it is that particular thing. The law takes into account that different terms might refer to the same thing. For example, “Clark Kent” and “Superman” are two different terms, but they refer to the same individual. A few comments need to be made about these three laws. First, the observation has been made that these three laws all seem to be saying the same thing. In a sense that is true. They mutually entail each other to the point where if one is true, then the others follow. However, they are distinct in that they each emphasize a different logical relationship, and in logical discourse, one law may be more useful than the other. Noncontradiction seems to have the primary force in most logical reasoning. However, excluded middle often is the best way to express a point in an argument. Second, as stated above, these laws are claims about existence. However, they can also be stated as claims about the truthfulness of a proposition. The law of noncontradiction can be stated: A proposition cannot be both true and false at the same time and in the same respect. The law of excluded middle can be stated: A proposition is either true or false. These both mean that no propositions are both true and false; they are either one or the other. If a person claims, “Last night I went to the store and bought ice cream,” and it turns out he went to the store but did not buy ice cream, then the proposition is false, not partly false and partly true. The third law can be stated: All true propositions are true, and all false propositions are false. Finally, these laws are not in need of any proof beyond themselves. They are self-evident and undeniable. By self-evident it is meant they prove themselves and do not need any proof outside themselves. Undeniable mean that the laws cannot be meaningfully denied. Any person denying these laws has to use them as the basis for the denial. Hence a denial would be self-defeating: she would be defeating the very point she is trying to make. The Language of Logic If philosophy is thinking critically about our beliefs, then logic can be seen as critically thinking about how we critically think. However, the word think may be too broad for our purposes. “Thinking” describes any mental activity, including remembering, daydreaming, supposing, believing, wishing and reasoning. Logic mostly concerns itself with the last of these. Reasoning is at the heart of what goes on in the process we have been describing as critical thinking. Logic employs established rules for correct reasoning, which we then use in evaluating our own reasons for the beliefs we hold. When we group our reasons together to achieve a particular conclusion, we refer to that as an argument. An argument is a group of propositions, some of which are reasons (called premises) trying to prove one of the other propositions (called the conclusion).
Notice the simple argument below: (a) All men are mortal. Socrates was a man. Therefore, Socrates was mortal. The first two propositions are the premises and the last is the conclusion. In addition to the premises and the conclusion there is a third element to an argument: the inference. The inference is the relationship between the premises and the conclusion. We use metaphors to describe this relationship. We will say either that the premises lead to the conclusion or that the conclusion follows from the premises. Note the following argument: (b) John Adams was the second president of the United States. The square root of 81 is 9. Therefore, I love pizza. In this argument we have two premises and a conclusion, but there is no inference between them. An argument put forth in which there is no inference is called a non sequitur, which means “it does not follow.” Logic is about evaluating arguments. Deductive arguments are evaluated as either valid or invalid. Inductive arguments are either strong or weak. If the conclusion follows from the premises, then it is either valid (if deductive) or strong (if inductive). Our first argument above is a valid deductive argument and the second is not. When it comes to the propositions within the argument we evaluate them according to their truth value: whether they are true or false. The validity or strength of an argument and the truth value of the propositions are two distinct and separate aspects of an argument. The truth value of the propositions in an argument has nothing to do with its validity or strength, and validity or strength has nothing to do with truth value. An argument can be valid or strong with all false propositions, and it can be invalid or weak with all true propositions. Look at the two deductive arguments below: (c) All cows are purple animals. All purple animals jump over the moon. Therefore, all cows jump over the moon. (d) All U.S. presidents have been male. Abraham Lincoln was male. Therefore, Abraham Lincoln was a U.S. president. In argument (c) all of the propositions are false, yet the conclusion is valid. This is because the conclusion follows from the premises whether they are true or not. In a valid deductive argument, if the premises are assumed to be true, then the conclusion follows. If all cows are purple and if all purple animals jump over the moon, then it would have to be the case that all cows jump over the moon. When we evaluate the validity of an argument, we are not concerned with whether the premises are true or not. We will discuss this more when we discuss deductive and inductive arguments below. Notice in argument (d) that all of the propositions are true, yet the argument is invalid. This is because the conclusion does not follow. The fact that all presidents have been male and that Lincoln was male does not lead to any conclusion. It happens to be true that Lincoln was president, but that does not follow from these two premises. You can easily test the validity of this argument by substituting the name of any male person in the second premise and will see immediately that the conclusion does not follow. This discussion brings out an important point: Do not assume that because you agree with the conclusion of an argument it must be a good argument. I have often heard arguments where I agree with the conclusion but thought the argument itself was poor. Be careful about proclaiming that an argument is valid or strong simply because you like its conclusion. A final term we need to introduce is soundness (for deduction) or cogency (for induction). A deductive argument is considered sound when it is valid and the premises are true. An inductive argument is considered cogent when it is strong and the premises are true. Argument (c) is valid but unsound because the premises are false. In order to be sound, a deductive argument must be both valid and feature all true premises. It is unsound if either the argument is invalid, at least one premise is false, or both. Only one of the above arguments is sound. Can you determine which? Deduction Deduction is a form of logical reasoning in which the aim is to arrive at a conclusion that is logically necessary given the premises. In a valid deductive argument, if the premises are assumed to be true, it is impossible for the conclusion to be false. It is important to note that this definition is not claiming that the premises are true. It claims that, if one assumes the premises are true, then the
conclusion must be true if the reasoning is valid. In a valid deductive argument, the premises guarantee the conclusion with logical certainty. The arguments we employed above previously were all deductive arguments, though they were not all valid. Argument (a) was a valid deductive argument. Assuming the premises are true, the conclusion follows necessarily. If it is true that all men are mortal and that Socrates was a man, then it must be true that Socrates was mortal. It is impossible for the conclusion to be false if the two premises are true. Argument (c) was also valid. In that argument the premises are not really true. However, assuming they are true, it is impossible for the conclusion to be false. It follows necessarily from the two premises: If it is true that all cows are purple and if all purple animals jump over the moon, then it must be true that all cows jump over the moon. The key distinctive of a deductive argument is the kind of conclusion that one is aiming to obtain: one that must follow given the premises. It is often claimed that a distinctive feature of deductive arguments is that they argue from the general to the particular. Although this is common, it is not the key distinguishing feature and is not always the case. Argument (a) follows this pattern but argument (c) does not. The key distinctive has to do with the kind of conclusion entailed. We will contrast this with induction below. There are many different forms of deductive arguments. An argument based on mathematics is a deductive form of reasoning: 265 + 573 = 838. The conclusion, 838, follows necessarily from the premises added together. The most common form of deductive reasoning is the syllogism. A syllogism is a logical argument that consists of two premises and a conclusion that is structured according to certain rules of valid inference that govern the particular type of syllogism being employed. If the syllogism keeps the rules, it is valid. If it breaks any of them, it is invalid. There are three different kinds of syllogisms that are based on three different kinds of propositions used in reasoning. The first of these is the categorical syllogism. A categorical syllogism consists of two categorical propositions as the premises and one categorical proposition as the conclusion. A categorical proposition is a statement that affirms or denies a relationship between two categories or classes: a subject and a predicate. The claim of a categorical proposition is that one of these categories is included or not included as a member of the other category. Here is an example: “All students are kind.” In this proposition it is being affirmed that all the members of the subject (students) are also members of the predicate (kind persons). As table 5.1 shows, there are four and only four kinds of categorical propositions. Each of these has a traditional letter name. Table 5.1 Name Type Model Example A Universal—Affirmative All S are P All students are kind. E Universal—Negative No S are P No students are kind. I Particular—Affirmative Some S are P Some students are kind. O Particular—Negative Some S are not P Some students are not kind. A categorical syllogism features three categorical propositions: a major premise, a minor premise and the conclusion. It also contains three terms and only three terms, each term being used twice. Here is an example: All M are P. (major premise) Some S are M. (minor premise) Some S are P. (conclusion) The term that appears in the predicate of the conclusion is the major term (P) and also appears in the major premise. The term that appears in the subject of the conclusion is the minor term (S) and also appears in the minor premise. The term that appears in both premises but does not appear in the conclusion is the middle term (M). In standard form the major premise is listed first. Since each categorical syllogism has three categorical propositions and there are four possible types of propositions, that means there are 256 possible forms of categorical syllogisms. Yet amazingly only twenty-four of these are valid. That is because they must conform to the six rules of valid inference for categorical syllogisms: (1) The middle term must be distributed at least once in the premises. (2) If a term is distributed in the conclusion, it must be distributed in the premise. (3) No conclusion can come from two negative premises. (4) If one premise is negative, then the conclusion must be negative. (5) If both premises are affirmative, the conclusion must be affirmative. (6) If both
premises are universal, the conclusion cannot be particular. Argument (d) is guilty of breaking the first rule. The term male is the middle term and is undistributed in both of the premises. Hence the argument is invalid. One evaluates a categorical syllogism by testing it by these five rules. If the syllogism breaks one or more of the rules, it is invalid. If it does not break any of the rules, then it is valid. Understanding the rules of the categorical syllogism and how they are employed takes a bit of practice and is beyond the scope of this chapter to cover in any detail. The second kind of syllogism is the disjunctive syllogism. A disjunctive syllogism makes use of the disjunctive proposition. A disjunctive proposition is an either/or statement that affirms or denies something in terms of two alternatives called alternants, as in the following example: “Either it rained last night or I left the sprinkler running.” This proposition offers two alternative possibilities about what happened. In a valid disjunctive syllogism, one will deny one of these alternatives in the second premise and affirm the other alternant in the conclusion: (k) Either it rained last night or I left the sprinkler running. I did not leave the sprinkler running. Therefore, it rained last night. The logic of this kind of argument can be seen as a process of elimination. If I have only two possibilities and I take one away, then the other must be true. Assuming the first premise is true, only two possibilities obtain. Assuming the second premise is true, I have removed one of the possibilities. Therefore, the conclusion is the only option left and must be true. The disjunctive syllogism is less complicated than the categorical syllogism, as there is only one rule. The rule states: One must deny one of the alternatives in the second premise and affirm the other alternative in the conclusion. Argument (k) followed this rule and is valid. However, what if we were to do this: (k 1) Either it rained last night or I left the sprinkler running It rained last night. Therefore I did not leave the sprinkler running. This syllogism is invalid. The reason is that my disjunctive proposition is inclusive, meaning it is possible that both alternatives could have happened: it could have rained and I could have left the sprinkler running. Therefore, affirming one of the alternatives in the second premise does not get me to any conclusion, because they can both be the case. (k 1) is guilty of committing the fallacy of affirming the alternant. The third kind of deductive syllogism is the hypothetical syllogism, which employs the hypothetical proposition. A hypothetical proposition is a statement that affirms or denies something in terms of an antecedent, expressed as an “if,” and a consequent, expressed as a “then.” Here is an example: Figure 5.1. This proposition is making a promise or guarantee. If you do the work, whatever that involves, then you will definitely pass the course. If this proposition is true, then it is impossible to do the work and fail the course. What happens if you do not do the work? Many logic beginners assume that this proposition necessitates that if you do not do the work, then you will fail the course. “After all,” they reason, “if doing the work guarantees that you pass, then not doing the work must guarantee you will fail.” That does not follow. The above proposition tells us only what will happen if you do the work. It is not claiming anything about what will happen if you do not do the work. It states a sufficient condition for passing the course. It does not state a necessary condition for passing the course. A sufficient condition states that this is one way of accomplishing the task. However, there may be other ways to pass the course (cheating, bribing the teacher), in which case doing the work would not be necessary. Understanding how a hypothetical proposition works is key to understanding the hypothetical syllogism. There are two basic kinds of hypothetical syllogisms: the pure and the mixed. The pure hypothetical syllogism uses only hypothetical propositions for the two premises and the conclusion: (l) If you do the work, then you will pass the course. If you pass the course, then you will graduate. Therefore, if you do the work, then you will graduate. The reasoning is pretty apparent in the pure hypothetical syllogism: If A, then B. If B, then C. Therefore, if A, then C. A mixed hypothetical syllogism employs a hypothetical proposition for the first premise but then uses categorical propositions for the second premise and the
conclusion. The key factor in determining validity in a mixed hypothetical syllogism is what is transpiring in the second premise. There are two forms of valid mixed hypothetical syllogism. The first form is called modus ponens (“the way of affirming”). In this form the second premise affirms that the antecedent of the hypothetical is true. Assuming the hypothetical is true, if the antecedent is affirmed, then the consequent must also be affirmed. Here is an example: (m) If you do the work, then you will pass the course. You did the work. You passed the course. If it is true that “if you do the work, you will pass the course” and “you did the work,” then it must be true that you passed the course. It is impossible for the conclusion to be false if the premises are true. Another valid form of the mixed hypothetical syllogism is called modus tollens (“the way of denying”). In this form the second premise denies the consequent of the hypothetical proposition. Assuming the hypothetical is true, if the consequent is denied, then the antecedent must also be denied: (m1) If you do the work, then you will pass the course. You did not pass the course. Therefore, you did not do the work. Again this conclusion must follow. How do we know you did not do the work? Because if you had, you would have passed. The first premise guarantees it. The two rules for the mixed hypothetical syllogism are either to affirm the antecedent or to deny the consequent in the second premise. The fallacies would be to do the opposite. Here are two examples: (m2) If you do the work, then you will pass the course. You did not do the work. Therefore, you did not pass the course. This syllogism commits the fallacy of denying the antecedent. Since doing the work is only a sufficient condition for passing the course, it is possible that there may be other ways of passing. Consequently, knowing you did not do the work does not warrant the inference that you did not pass. The argument is invalid. (m3) If you do the work, then you will pass the course. You passed the course. Therefore, you must have done the work. This syllogism commits the fallacy of affirming the consequent. Again, the first premise allows for the possibility of other ways to pass the course. Therefore, the conclusion does not follow that you did the work, as you may have passed some other way. Induction Perhaps the best way to understand inductive logic is to contrast it with deductive logic. As we noted above, in a valid deductive argument, the conclusion follows necessarily from the premises. So, if the premises are assumed to be true, the conclusion necessarily must be true. It is impossible for the conclusion to be false. This is never the case for an inductive argument. In a strong inductive argument, the conclusion only probably follows from the premises. That is, assuming the premises are true, the conclusion is only probable. It never follows necessarily as in deduction. This is the key distinction between the two kinds of reasoning. No inductive argument reaches a conclusion that is logically certain in the same way as a deductive argument—even if the premises are true. An example might help. Suppose I have a class of twenty students and, as they are coming into class, I observe each student individually, noticing that each is wearing a red T-shirt. Eighteen students have arrived, all with red T-shirts, and I draw the conclusion, “Since the vast majority of students in this class are wearing a red T-shirt, probably the last two will come in wearing one as well.” Can I be logically certain of this conclusion? No. Why not? Because to be logically certain means that, if the premises are true, it is impossible that I could be wrong. But that is not the case here. The reason that deduction reaches logically certain conclusions is that everything in the conclusion is already contained in the premises. A valid syllogism is thus based purely on the structural relationship between terms in the premises. We do not even need to use words to determine whether a deductive argument is valid or not: (n) All Z are N. All N are H. All Z are H. The above argument is valid even though we are not told what the letters stand for. However, inductive arguments reach conclusions that are intended to go beyond the information contained in the individual premises. In our above argument each premise was of an individual student wearing a red T-shirt. However, the conclusion contained more information than each premise
individually; it attempted to reach a conclusion about the last two students. Thus, arriving at an inductive conclusion cannot be achieved with the same logical certainty as a deduction. Another distinction between deductive and inductive reasoning concerns how the two kinds of arguments are evaluated. Deductive reasoning has only two possible evaluations: the argument is either valid or invalid. However, in evaluating inductive arguments a number of options are possible. In general the two major alternatives are strong or weak. A strong inductive argument is one where, assuming the premises are true, the conclusion probably follows. A weak inductive argument is one where, assuming the premises are true, the conclusion probably does not follow. Unlike deduction, these two alternatives admit of degrees of probability. The conclusion for a strong argument could be extremely probable, very probable, somewhat probable or a little probable. The same degrees are possible of weak arguments. What renders an argument more or less probable depends on the quantity or quality of the evidence supplied in the premises. Arguments that have either a great deal of evidence or evidence of a higher quality will be stronger than those that do not. Suppose I tell you that McDonald’s is serving free cheeseburgers today. You are skeptical, and so you ask for evidence of my claim. I say, “Because they served free cheeseburgers on this day last year.” Now, assuming this is true, is it more or less probable that they are doing so today? Most would admit that the probability is pretty low. Just because something happened a year ago on this day is not enough in itself to claim it will happen today. So you ask me for more evidence, and I tell you that someone I trust told me that they were serving free cheeseburgers today. That is a little better, but most would still be skeptical on the basis of such little evidence. This third person could be wrong. Suppose I then tell you that along with these two facts, I also read in the paper that McDonald’s is serving free cheeseburgers because they are celebrating the founding of the restaurant today. At this point you would begin to take the claim seriously. Finally I take you to a McDonald’s, where we order cheeseburgers and they do not charge us. Here you would probably say that I have provided you with enough evidence to evaluate the claim that McDonald’s is serving free cheeseburgers today as highly likely. Is it certain? No, but all the evidence points in that direction, and you can feel confident of the claim being true. Inductive arguments are often said to reason from the particular to the general. Although this is often true, it is not always the case. In the argument about red T-shirts, we did argue from observing individual instances to a general conclusion about the class as a whole. However, one can also argue from one particular to another particular inductively, as in an analogy (see below). So while it is often the case that induction goes from the particular to the general, it is not always the case. Like deduction, inductive arguments come in a number of different forms. Let us look at six of them. Generalization is probably the most common form of inductive reasoning. In this form a number of particulars are gathered and a general conclusion attained. The example of the red T-shirts employed this method. Here is another example: A large number of college students are individually observed. A significant majority of them made better grades after taking a course in college studying strategies. Therefore, it is probable that taking this course results in better grades. Because there are a number of variables that need to be taken into account, we cannot be certain of our conclusion. But assuming that this is the one factor these cases have in common, our conclusion is justified with some degree of probability. A second form of inductive reasoning is the analogy. An analogy is a one-to-one comparison between two or more things or states of affairs. The analogy is successful observing relevantly similar particulars and can arrive at a probable conclusion based on that similarity. Suppose Gary buys a new 2012 Porsche 911 from the local dealer. It has a manual transmission with a six-cylinder engine and gets 26 mpg on the highway. Sal also buys a new car and gets the same make with the same features from the dealer. By analogy we can say that if Gary’s car
gets 26 mpg, then Sal’s will probably get about the same. We are analogizing from Gary’s car to Sal’s car, and we can reach this conclusion because of the similarities of the cars concerning the issue under consideration: gas mileage. Analogies are successful only as far as the discussion concerns areas relevantly similar to the issue under consideration. A third form of inductive reasoning is predictions based on the probability calculus. This form of argument makes a prediction about a future event based on our past experiences in light of current conditions. Meteorologists often reason this way. They study current local and regional conditions such as temperature, barometric pressure, wind speed and direction and then, based on previous experiences with these conditions, predict the weather over a period of time. The meteorologist cannot be certain of her predictions (so do not blame her if she is off at times) because she may not know all the variables in play. She can predict only on the basis of what she does know. Hence she will usually express predictions in terms of percentage: “There is an 80% chance of rain on Tuesday.” Predictions are often made in other areas as well, such as the stock market and the outcome of a football game. All these use inductive reasoning. A fourth form of inductive reasoning is statistical reasoning. This occurs by gathering information from a sample population and attempting to extrapolate general trends, averages and percentages based on principles of statistics. Statistical reasoning plays a large part in scientific, psychological and academic studies, but most of us encounter it in the use of polls. A newscaster might say, “The president’s approval rating rose by 8 percent last month according to a new Wall Street Journal poll.” Some erroneously assume this means that 8 percent of all adult citizens think more highly of the president than in the previous months. However, the Wall Street Journal did not arrive at that number by polling the entire adult population of the United States. A typical national poll usually considers eight hundred to one thousand people. The polling firm determines a sample population, asks their views about the president and then extrapolates from the sample what the whole country is thinking. The key to a successful extrapolation depends on a number of factors, including the size and representation of the sample, the phrasing of the questions and the manner in which the report is expressed. Statistical reasoning is a useful and effective way of arriving at an inductive conclusion, but one should cautiously examine the method and means of a particular poll or study, verifying that it was carefully done according to proper rules and guidelines. It is often said that numbers don’t lie, but they can be misused and even distorted to mislead people into believing conclusions that are not necessarily true. A fifth form of inductive reasoning is the causal inference. This is done by observing an effect and attempting to reason back to its cause. For example, if I attempt to start my car and nothing happens, I reasonably infer my battery is dead. The reason this is the first assumption is that in the experience of most people it is the most common reason the engine will not turn over. Other reasons are possible, such as the starter motor not functioning, but they are less common. I form a hypothesis as to what caused the effect, and then I test the hypothesis. Once I remove one possible alternative, I move on to the next. I remove the other possible alternatives and arrive at the cause. This is sometimes referred to as the scientific method or as hypothetical reasoning. A final form of inductive reasoning is an argument based on authority. The evidence cited to support a conclusion is some form of authority. It can be a person, an authoritative writing or an authoritative sign. For example, if you are driving down the road and you see a sign saying that there is a left curve ahead, it is reasonable to believe the sign because signs are generally reliable. It is always possible they can be wrong, but experience informs us that is the exception, not the rule. When it comes to persons and writings, more caution is advised. We recognize experts in some areas, such as science or history, but in other areas, such as politics, religion and ethics, we do not recognize definitive experts. For example, just because John Stuart Mill wrote a lot about ethics does not mean that he is an expert at what would be
the right thing to do in a particular situation. It is recognized that there are many different views in these areas and therefore there is no one expert to appeal to for the definitive answer. Also, while an individual might be an expert in one area, such as science, that does not make him an expert in other areas, such as philosophy. Finally, even qualified experts can be wrong. Their testimony can add evidence for a conclusion, but caution is advised about arriving at a conclusion purely because someone says it is the case. We looked at a number of fallacies under deduction. These are sometimes referred to as formal fallacies, for the error is usually structural. Fallacies also exist for inductive reasoning. They fall under the category of informal fallacies and will be covered in the next chapter. Addendum Exercises Logic is a skill, and skills are learned by practice. Below are some exercises to help you better grasp the material covered in this chapter. Answers are at the end of the book. For each exercise, try to identify the following: • What type of argument is it: deductive or inductive? • What the form of the argument? If deductive, is it a categorical, disjunctive or hypothetical syllogism? If inductive, is it a generalization, analogy, prediction, statistical reasoning, causal inference or argument based on authority? • If deductive, is it valid or invalid? If inductive, is it strong or weak? 1. Lisa is a student who understands logic.Some students who understand logic will get an A. Therefore, Lisa will get an A. 2. The burglar must have been a tall, heavy man. His footprints sink an inch into the dry soil, and he wears a size fourteen shoe. Also, we found blood and hair on the rafter where he appears to have bumped his head. 3. If Chicago is a city in Illinois, then the Yankees will win the pennant. Chicago is a city in Illinois. Therefore the Yankees will win the pennant. 4. Either Dana went to the movies or he went to the library. Dana did not go to the movies. Therefore he went to the library. 5. This clay tile is the exact same brand, manufacturer and model of tile I laid on my patio last summer. Since the tile on my patio scratches very easily, it is likely that this tile will scratch easily. I wouldn’t advise you to buy it. 6. The Green Bay Packers have won seven out of their last eight games, and the Detroit Lions have not won a single game all season. But the Lions can’t keep losing forever. Therefore the Lions will probably beat the Packers in this Sunday’s game. 7. If deism is true, then the Bible is false. But deism is false. Therefore, the Bible must be true. 8. I went out to my car this freezing cold morning and I could not get it to start. My neighbor’s teenage kid probably poured sugar into my gas tank. 9. All animals who speak French have good artistic talent. My dog Toby speaks fluent French. Therefore, Toby has good artistic talent. 10. If objective morality exists, there must be a God. Objective morality exists. Therefore, there must be a God. 11. Dr. Jones, the eminent physicist, believes in psychic phenomena like ESP and ghosts. Given his expertise as a physicist, we should believe in such phenomena as well. 12. In a recent poll of seven thousand college students on a variety of campuses across the country, it was discovered that a large majority of them began drinking alcohol while in high school. It appears that we may have a serious teenage drinking problem in this country. 13. Either Phyllis will go to the conference or Stuart will attend. Phyllis is going to the conference. So Stuart will not attend. 14. If this syllogism commits the fallacy of affirming the consequent, then it is invalid. This syllogism does not commit the fallacy of affirming the consequent. Therefore, this syllogism is valid. 15. Most of the students attending Liberty University are Christians. Kelly is a student at Liberty University. Therefore it is likely that Kelly is a Christian. Six Informal Fallacies A number of years ago I was walking along the streets of New York City when I came to a street magician performing card tricks before a small crowd. I stopped to watch and became fascinated with his sleight-of-hand abilities. At one point he turned to me and asked if I would like to play a game. The game was called three-card monte and was simple to play. He pulled out three cards; two were jokers, and the third was the ace of spades. He allowed me to examine the cards, and I noticed there was nothing special about them except for a slight bend lengthwise down each card that allowed one to easily pick up
the cards when they were laid down on the table. He laid the cards face up in a row, with the ace in the middle. “Now,” he said, “this is an old con game where the innocent spectators often lost their money betting against the dealer. We are not going to do any betting, but I will show you how the game was played. I am going to turn the cards over and mix them up a bit. After I am done, all you have to do is tell me which one is the ace.” I felt pretty good about my powers of observation and figured I could beat this guy, so I agreed. He flipped the cards over and began quickly shuffling them around on the table. I watched carefully, keeping my eye on the center card as it moved around the table. After a few seconds of shuffling he stopped, lined up the cards in a row and asked me to choose the ace. I felt confident that I had followed his movements and pointed to the card on the right. He asked me to turn it over. I was wrong—it was one of the jokers. The ace was on the left. “The first time is always the hardest,” he said. “Now that you have seen it, let me do it for you again.” Again he turned the cards over, and again I watched carefully as he shuffled them around. When he stopped this time, I was sure I had the correct card. “It’s in the middle,” I proclaimed. When I turned it over, I was again disappointed to see a joker. The ace was on the right this time. He then said, “I will do it one more time real slow. See if you can follow the ace.” I was sure if he went just a little slower I could catch him. He flipped over the cards, but this time shuffled them slowly around the table. I was amazed at how slowly and deliberately he moved the cards. I remember thinking, “Oh, this is just too easy.” I effortlessly followed the ace, and when he stopped shuffling, I reached down triumphantly and turned over … a joker. I stood there staring at the card in my hand as the group of spectators laughed at my misfortune. I could not believe he had fooled me again. I knew he was doing some sort of sleight of hand, but for the life of me I could not discern what it was. Informal fallacies are a little like that. We know something is wrong, but it is not always easy to discern where the error lies. In chapter five we examined some fallacies of deductive logic. Deductive fallacies occur when a specific rule of valid inference is broken. These are called formal fallacies because they break a formal rule. However, some fallacies do not break a formal rule, yet there is still something wrong with the reasoning. These are called informal fallacies. Whereas formal fallacies concern structural relationships, informal fallacies are often more concerned with the content of the argument. Observe the following argument: (a) The Indian is a vanishing American. That man over there is an Indian. That man over there is vanishing. If you were to apply the rules of valid inference to this categorical syllogism, it would seem to be valid, as it appears to keep all of the rules. We know, however, that this cannot be a valid syllogism because it does not make sense. The fallacy committed here is not a formal fallacy but an informal fallacy. It is not easy to provide a precise definition of informal fallacies, but several standard ones have been identified. In general they fall into one of the following four categories: fallacies of weak induction, fallacies of presumption, fallacies of ambiguity and fallacies of relevance. Let us look at some classic examples of each of these. Fallacies of Weak Induction In this first group of fallacies, an error arises because the reasoning between the premises and the conclusion is inductively weak and leads us to a conclusion that may be presented as strong but does not follow. Hasty generalization. As the name implies, this fallacy occurs by arriving at a conclusion on the basis of insufficient evidence. Hence our conclusion is arrived at hastily. In chapter five we discussed the inductive method of generalization, in which a number of particulars are gathered together and a general conclusion is obtained. The success of that method depends on gathering an adequate representative sample from which we can reach a conclusion. In hasty generalization, our representative sample is qualitatively or quantitatively inadequate to reach any conclusion. Here is an example: Years ago I owned a Ford, and I always had problems with it. My dad also owned a Ford when he was younger, and he told me it was always in the shop getting fixed. The conclusion is obvious: Ford makes nothing but
lemons. Considering how many automobiles Ford sells a year—more than two million in 2011—and the lengthy time frame involved in this argument, it is highly unlikely that a conclusion can be reached on the overall quality of Ford automobiles on the basis of two cars, both of which were manufactured some years ago. This conclusion is too quick and based on insufficient evidence, so the argument is weak. Accident or sweeping generalization. The fallacy occurs by applying a general principle to a specific case to which that principle does not apply. This fallacy often results from a tendency to confuse general principles with hard-and-fast absolutes and then apply these to each and every case without considering possible exceptions. This is not to deny the existence of absolutes, but it is to recognize that some principles were never meant to be taken as such. This fallacy sweeps everything together without taking into account relevant distinctions that make a difference. Note the following examples: The Constitution guarantees freedom of religion. Therefore the Church of Divine Enlightenment, which practices child sacrifice, should have the freedom to continue with its unique form of worship. Property should be returned to its rightful owner. Therefore you should give your drunken friend’s car keys to him when he asks for them. Running is good exercise. Therefore everyone should run several miles a day. All of these contain good general principles, but they are not absolutes. Some forms of worship might be immoral or illegal, and our constitutional guarantee was not designed to support such activities. A right to private property is a good principle, but there are situations that justify overruling that right. And running is good exercise, but some people should not participate in so strenuous an activity. Well-intentioned Christians can be notorious at committing this fallacy. Some will often take a scriptural principle and turn it in to an absolute promise. Parents claim the promise of Proverbs 22:6 (KJV), “Train up a child in the way he should go, and when he is old, he will not depart from it,” only to be disappointed when their child becomes rebellious. Part of the problem is that they are treating a proverb as if it is a promise. Proverbs are bits of wisdom that, if followed, typically lead to good consequences, but they are no guarantee, and treating them so leads to the fallacy of sweeping generalization. Weak analogy. As we noted in the previous chapter, an analogy is a comparison between two or more things or states of affairs. The success of an analogical argument depends on the relevant similarities between the items being compared. A weak analogy occurs when the items being compared are not relevantly similar concerning the issue under consideration. They might be similar in some respects, but they are not similar enough relevant to the issue. Look at this example: Consumers, who pay for their purchases, get to select what they want when shopping based on their own personal preferences. Therefore college students, who pay for their education, should be allowed to pick which courses, assignments and tests they want to take based on their personal preferences. While it is true that consumers and college students are similar in that both are paying for what they are receiving, that is where the comparison ends. Shopping and getting an education are very different. In getting an education students are often unaware of the material they need to learn and what is involved in understanding it. So they need experts, like college professors, to guide them in selecting courses, fulfilling assignments and evaluating them on their progress. This is hardly the same as buying a pair of shoes. Should you encounter an argument based on analogy, ask yourself, “Is the comparison based on a relevant similarity?” False cause. This fallacy is committed when we attempt to draw a causal inference between two events and there is little evidence that the two events are causally connected. One version of this is the well-known post hoc fallacy. In this version of the fallacy, an individual mistakenly concludes that because one event occurred temporally after another event, the first event must have caused the second. Many of us have heard people say, “I knew it would rain. I just washed my car.” Of course few of us take such claims seriously—washing cars has nothing to do with precipitation. However, it is not uncommon for a person
to draw a causal inference between two events without providing evidence and therefore be guilty of the post hoc: Studying philosophy will cause you to lose your faith. I know that because my brother Mike took a course in philosophy at college. Soon afterward he dropped out of school, stopped going to church and got heavily into drugs. Asserting that philosophy was the cause of Mike’s decline does not follow. There may be many reasons why he changed. To select philosophy as the sole reason he changed simply because he studied it before he adopted these behaviors provides no evidence that it was the cause of his change. Here is another example: Christianity is just a myth built on earlier pagan myths that also had some sort of savior-god who was “born from a virgin” and “rose from the dead.” There a number of problems with this common criticism of Christianity, the main one for our purposes being this: because an earlier religion may have similar claims to Christianity does not by itself constitute evidence that the cause for Christian beliefs is that earlier source. A second type of false-cause argument is the oversimplified cause. Often there may be more than one cause for an event, or it may be the result of a causal series. Care needs to be taken that we do not reduce a complex problem to a simplistic cause. The argument about Mike above is a good example. The causes for a dramatic change in Mike’s lifestyle are probably due to a number of social, psychological and moral concerns. It is naive at best to identify just one cause for such a complicated problem. The tendency to oversimplify, as lamentable as it is, is rampant in a culture that continually reduces complex ideas to thirty-second sound bites. A third type of false-cause fallacy is the non causa pro causa (“not the cause, for the cause”). This fallacy occurs when something that is not the cause is inferred as being the cause for an event or effect with no evidence offered to support the inference. Unlike the post hoc fallacy, this version of the fallacy does not involve temporal succession. For example, oftentimes things are mistakenly causally related when there is little relation between them: No wonder there are random acts of violence in our schools today. Just look at all the violent video games out there and the amount of violence on television and in the movies. It may be the case that there is a causal connection between violence in the media and violence in our schools, but evidence and an argument are needed to establish a causal connection. Just because both involve violence is not enough in itself to support the inference that one caused the other. Perhaps they are both caused by a third entity, such as an overall moral decline in modern society. Another type of the non causa fallacy is when cause and effect are interchanged: The students who best understand the material will get the best grades. Therefore if we give Bill a high grade then he will understand the material. The mistake in this case is confusing the cause with the effect. Being a good student causes one to get high grades, but getting high grades does not cause one to be a good student. Slippery slope. The slippery-slope fallacy is usually considered a fallacy of its own, but it can be seen as a type of the false cause fallacy. It is a weak inductive argument that claims that given one event, an alleged chain of events will follow, but it offers little or no evidence to support such a claim. In most cases it is claimed that the chain will result in some disastrous consequence. This is an example of superlative arguing. The arguer attempts to make a case by arriving at an extreme conclusion that often overstates the actual situation. The key characteristic in the slippery-slope argument is its successive step-by-step development. Here is an example: If a person gives up his belief in the inerrancy of the Bible, it won’t be long before he stops believing in inspiration. If he stops believing in inspiration, he will begin to question all his religious beliefs. He will begin to doubt in God’s existence. The end result will be that he will become an atheist and a moral reprobate. Such an outcome might occur should a Christian deny inerrancy, but it is not inevitable. Many Christians have questioned inerrancy and arrived at a different outcome from the one suggested here. Slippery slopes are notorious for predicting unwarranted extreme outcomes. Not all slippery-slope arguments are fallacious. If you can demonstrate a causal relationship that has strong
evidence supporting a series of events leading to an outcome and you are careful not to overstate the case, then this would be a good argument. Scientists often predict the outcomes of a series of events this way, which is an acceptable form of arguing. It is a question of how much evidence you have and how precise and principled you are in employing it to reach a conclusion. Fallacies of Ambiguity Fallacies of ambiguity are a family of fallacies arising from language problems. The language employed might be unclear, vague, ambiguous or inappropriate in some other sense. Since philosophers seek clarity in presenting and evaluating arguments, they value language that is precise and accurate in expressing ideas. Here are some fallacies of ambiguity. Equivocation. This fallacy occurs when the meaning of a significant term changes in the middle of an argument and thus distorts and usually invalidates the conclusion. In the English language we have a number of terms that can have more than one meaning. For example, think of the many meanings of the word trunk: the back of a car, the bottom of a tree, the snout of an elephant or a large crate in which one would pack clothing. Because of the flexibility of English, it is easy to begin an argument with a term having one meaning and to use the same term with a different meaning later in the argument. The fallacy about the Indian as a vanishing American at the beginning of this chapter is an example of this fallacy. There are two equivocations in that example. First, the term vanishing changes in meaning from a figurative to a literal use, and, second, the term Indian changes from a class distinction to a particular reference. Here are some other examples: A woman has a legal right to an abortion. Therefore it is perfectly right for Susan to abort her unborn child. Investigative Reporter: “People often accuse me of being sensationalistic. Well, I happen to think there are some stories that are pretty sensational.” Some argue that the publication of pornography is not in the public interest. However, I know many persons who are very interested in viewing pornography. Probably fewer words are more often equivocated than the word right. In the example above, there is a significant difference between an action being the right thing to do (a moral concept) and one having a legal right to something (a legal concept). The two uses of “right” do not mean the same thing. In the second example, “sensational” means “highly unusual” while “sensationalistic” means treating something that is usual as if it is highly unusual. Finally, in the last example, the term “public interest” means what is best for the welfare of the public at large, but we all know that because of our weakness and fallen state, we are often interested in things that are not in our best interest. Hypostatization. This fallacy occurs when one treats an abstract word as if it were a concrete word. Concrete words refer to particular objects such as the round table. Abstract terms refer to general qualities such as roundness. The most common form of this fallacy is through personification, or the attributing of personal characteristics to nonpersonal things. In hypostatization the nonpersonal things that are personified are abstract concepts. This may be an accepted practice in literature and poetry, but it is fallacious in argumentation because it introduces a certain amount of vagueness and distortion into the argument. Here is an example: It is perfectly legitimate to eliminate the mentally feeble from society through eugenics. For just as nature in her mercy selects the fittest to survive and eliminates the lame, so we too are merciful helping nature in her process of keeping society fit. “Nature” is a common theme employed in this fallacy. Nature does not have the ability to select or be merciful; only persons do. This might make for good poetry, but it distorts the argument to employ such language, and the result is a questionable conclusion. Another abstract term commonly personified is culture, as in “Morality is culturally determined.” In truth culture cannot determine anything. Culture is an abstract term used to describe the general beliefs and practices of a community of persons. Culture may describe the way a community acts, but it does not prescribe how a community should act. Other abstract terms that are often employed in this fallacy are science, society, government and truth. Amphiboly. An amphiboly is a well-known fallacy that is usually the result of
ambiguous grammatical construction or poor sentence structure that introduces a lack of clarity in the sentence. One of the most common versions of this fallacy occurs when the referent of a pronoun is not clear: “Paul told David that he was mistaken about his solution to the problem.” The difficulty here is that one is not sure to whom the pronoun “he” is referring. Was Paul telling David that Paul himself was mistaken, or was Paul telling David that David was mistaken? Here is another example: “If you don’t go to other people’s funerals, they won’t go to yours.” It is not clear precisely who “they” are referring to in this sentence. Amphibolies are commonly found in writings where brevity is necessary, such as signs, newspaper headlines and advertisements. We get little context in helping us figure out the meaning. They also often produce humorous effects. Here are some examples: Toilet Out of Order … Please Use Floor Below We Exchange Anything—Bicycles, Machines, Etc. Why Not Bring Your Wife Along and Get a Wonderful Bargain Panda Mating Fails; Veterinarian Takes Over Enraged Cow Injures Farmer with Axe Two Sisters Reunited After 18 Years at Checkout Counter Composition and division. These are two separate fallacies, but because the reasoning is similar in both, I will discuss them together. Composition and division are known as part/whole fallacies because it is erroneously assumed that what is true of one must also be true of the other. In the fallacy of composition, it is erroneously thought that what is true of each part of something must necessarily be true of the whole. This sometimes is true, but it is not necessarily the case. One has to look at the context of the argument to see whether the fallacy applies or not. Here is a clear example of the fallacy: Each member of Chicago Cubs is a great baseball player. Therefore the Cubs must be a great baseball team. Even if it is true that each member of the Cubs is a great baseball player, it does not necessarily follow that they are a great team. There is more to being a great ball team besides having individually great players. They must play well together. There is a property that is present in the team that is not present in each individual player: synergy. Synergy is the interaction of elements that when combined produce a total effect that is greater than the sum of the individual elements by themselves. Division is a fallacy that makes the same error in the opposite direction. It erroneously assumes that what is true of the whole must also be true of each individual part. We can use a similar example to demonstrate this fallacy: The Los Angeles Dodgers are a great baseball team. Therefore each individual member must be a great baseball player. Again the conclusion does not necessarily follow. Many of us have played on teams where the team has done very well despite some weak players. Sometimes a few great players are enough to carry the team to victory. One needs to approach this fallacy with some caution. It is not always obvious when the fallacy is being committed and when the reasoning is legitimate. If each and every part of a fence is white, then one can nonfallaciously argue that the entire fence is white. One needs to look at the context to see whether the fallacy is present or not. Many theists have argued that every part of the universe is contingent, so the universe as a whole must be contingent. If every contingent thing needs a cause, then the universe needs a cause. Some atheists have argued that this argument is guilty of the fallacy of composition, but whether or not it is depends on whether the universe is equal to the sum of its parts or is greater than the sum of its parts. There are other fallacies that fall under the category of language issues that do not have specific names. One is the use of emotionally loaded and cliché language. People are often passionate about the beliefs they hold. This may cause them to use language that packs an emotional wallop but may not be accurate and may even be misleading in arguing for a particular view. For example, in debates about abortion we often hear proponents argue that if we repeal Roe v. Wade we will return to the days of back-alley abortions. This phrase is used to elicit an emotional response by painting a horrible picture in the minds of the listeners. Such a picture aims to distract the listeners from the real issue of whether taking the life of the unborn is morally appropriate. Caution is vital in a culture
in which emotional appeals are a common form of persuasion. Oftentimes it is warranted to pause, reflect and ask how accurate are the portrayals of the issue at hand. Sometimes arguers will appeal to clichés, epithets and pithy sayings to sway an opponent in a particular direction. For example, on the question of the morality of homosexuality one is likely to hear the term homophobia used against those who have moral problems with the acceptance of homosexuality as a legitimate alternative lifestyle. Is this the appropriate term? A phobia is a psychological aberration which results in an irrational fear of something. By this description, homophobia would be an irrational fear of homosexuality or homosexuals. It may be true that there are genuine cases of homophobia, but one needs to be careful in making such a diagnosis in the absence of a qualified psychological assessment. One cannot claim that individuals are homophobic simply because they have moral problems with homosexuality. Most of us have moral problems with murder, but I have never heard anyone claim that it is because we are “murderphobic.” What has happened is that the term homophobia has become a cliché. It is a rhetorical device meant to persuade the listener without contributing anything to the discussion concerning the morality of homosexuality. Clichés cannot stand in for well-thought-out arguments. Fallacies of Presumption What is the difference between an assumption and a presumption? Although the terms are often used interchangeably, there is a subtle difference between them. To make an assumption is to take something for granted without investigating it. For example, when I sat down at my computer to type this chapter, I did not investigate the chair to see whether it would hold my weight. I assumed that it would. A presumption is like an assumption with a small twist. Again I am assuming without investigation, but in the case of presumption an epistemic obligation exists that usually is not present with a simple assumption. We recognize that many assumptions are reasonable and are not in need of investigation. Imagine what life would be like if every time we were to sit in a chair we had to take the time to see whether it was constructed well enough to hold us. We have enough experience with chairs to feel confident that they will hold our weight and do not feel the need for constant investigation. Some claims, though, should be investigated before we believe them, and to ignore this obligation is to be presumptuous. The fallacies of presumption occur when one is not given the opportunity to investigate all of the options in an argument because the argument has been framed and presented in such a way as to ignore, distort or evade certain facts that may have significant bearing on the argument. Begging the question. This may be the most well-known fallacy of presumption. In this fallacy the main question or premise under debate is never addressed. Instead, the arguer presumes the issue is settled or does not need to be addressed and arrives at a conclusion without presenting the premise or allowing others to examine it. A common form of the fallacy leaves out the key premise in an argument. Note the following examples: Killing an innocent human person without just cause is murder. Therefore abortion should be illegal. Most paraplegics do not have the ability to take their own lives. Therefore physician-assisted suicide should be made available for them. In both of these examples presumptions are made that are key premises to the argument and should be presented and discussed. However, the manner in which the argument is presented leaves these key premises out and presumes that everyone is settled on these issues. In the first example, the hidden premise “Fetuses are human persons” is highly debated and needs to be addressed and defended. In the second example, the hidden premise is “Suicide is morally acceptable for paraplegics.” Again, that is open to debate and should be presented for discussion and debate. Sometimes begging the question occurs when the conclusion merely restates a premise. This is often done by using different language when moving from premise to conclusion, thereby concealing the fallacy. By placing the conclusion in the premises the arguer presumes that the conclusion is true in order to prove that it is true. Note this example: Capital punishment is justified for the crimes of murder
and kidnapping because it is quite legitimate that someone be put to death for having committed such hateful and inhumane acts. Notice how the conclusion says the same thing as the premise. You might not see it until you analyze the terms: “capital punishment” = “putting someone to death,” “justified” = “it is quite legitimate” and “murder and kidnapping” = “such hateful and inhumane acts.” All this argument is saying is “capital punishment is justified for murder and kidnapping because capital punishment is justified for murder and kidnapping.” No reason is offered for the justification of capital punishment. The conclusion is presumed to be true. A third type of begging the question is the circular argument. In this form the premise itself needs justification, and the arguer justifies it by appealing to the conclusion: We know the Bible is the inerrant Word of God because it says in 2 Timothy 3:16 that “All Scripture is inspired by God,” and God cannot lie. In his opinion on Roe v Wade, Justice Blackmun of the Supreme Court claims that the state has an interest in protecting fetal life only when that life can live outside the womb. This is because, we are told by him, prior to being outside the womb the fetus has no interests or rights. Aristotle taught that the “good” is whatever the good man approves of, and you can tell a good man because he always approves of the good. The first example is circular, as it is using the Bible as the inerrant Word of God to prove that the Bible is the inerrant Word of God. In the second argument Justice Blackmun is using the fact that the fetus has no interests or rights to prove that the fetus has no interests or rights. In the final example the argument is circular because in order to find a good man I have to know what the good is, and I can know that only by knowing what a good man approves of, but I can know that only when I find a good man. Bifurcation. This fallacy is sometimes referred to as the false dilemma or the fallacy of extremism. The fallacy occurs when we are presented only two possible options, usually extremes, when other options are possible. The fallacy presumes the two options are the only ones and does not allow us to consider other possibilities. It is common to see this fallacy employed by politicians, especially in the present climate of extreme partisanship: Either you support the president’s policies concerning health insurance or you are not a loyal American. It seems to most people that a third alternative is possible wherein one can disagree with the president and yet remain a loyal American. Disagreement hardly makes one disloyal. I grew up during the late 1960s when the country was divided over the Vietnam war. Extreme positions were often taken on both sides of the debate. You were labeled as either a hawk or a dove. A famous bumper sticker of the time declared, “My Country: Love It or Leave It.” The idea is that if you were not 100 percent in favor of the war, then you had only one option: leave. However, other options were possible. You might show love of country by raising your voice in protest when you believe the country is going in the wrong direction. We see much of the same problem in current times. Today you are labeled as a member of either the religious right or the liberal left. Little concern is given other options. The fallacy of bifurcation flourishes in such an environment. Bifurcation occurs often with extreme terms like never and always. But rarely are these two options the case in reality. When a person claims, “You never do anything right,” she is bifurcating the issue. It is difficult to believe that anyone “never” or “always” does everything right. None of this is to deny that sometimes there are only two options. When that is the case, one is not guilty of this fallacy. For example, the law of excluded middle tells us that something either exists or does not exist. There is no middle ground. Similarly, a person can be either dead/alive or male/female. In these cases there are only two options. One is only guilty of the fallacy of bifurcation when there are more than two options but only two are considered. Special pleading. This fallacy occurs when one applies a double standard without warrant: one standard for us and another for them. It is important to note at the outset that not all double standards are illegitimate. For example, I had different standards for my children at different stages of their development. When my eldest was sixteen she was allowed certain
privileges that her much younger sister did not have. Similarly, faculty are allowed certain perks that students are not. Such double standards are warranted. Unless there are justifiable reasons, however, many double standards are not legitimate. This is a fallacy of presumption because a double standard is erected without justification. Some years ago I heard a conservative radio commentator lambast the “liberal media” for treating their readers like they were idiots by commenting on a presidential debate. “They think you can’t figure out for yourself what is going on and that you need them to explain it all to you.” Immediately after concluding his tirade he said, “Now let me tell you what really happened in that debate.” That is special pleading: They are treating you like idiots, while I am helping you to understand. The above example demonstrates a common way this fallacy is committed: through the use of pejorative and euphemistic language. To speak euphemistically is to put something in its best light, making it sound better that it may be. To speak pejoratively is the opposite: to place something in a negative light, making it sound worse than it is. Notice this example from S. Morris Engel’s classic work on informal fallacies, With Good Reason: The ruthless tactics of the enemy, his fanatical, suicidal attacks, have been foiled by the stern measures of our commanders and the devoted self-sacrifice of our troops. Note the language: when we speak of the enemy we refer to his “ruthless tactics” that are “fanatical” and “suicidal.” When we speak of our troops we call our tactics “stern measures” and the actions of our troops as “devoted” and “self-sacrificial.” There may in fact be little difference between the two actions. Here are some other examples that use the same device: I firmly believe that if you weren’t so stubborn, you’d agree with me. Our group of citizens is being disturbed by that gang over there. Your party is noisy. We are just being active. I am thrifty. You are stingy. Complex question. Our last fallacy of presumption occurs when a question is asked that contains two questions but is phrased so that the responder can give only one answer and is not allowed to address both questions separately. The result is that the responder may end up affirming or denying something he does not intend to. Some examples will help: How long have you been beating your wife? How many cookies did you steal from the cookie jar? Were you being dishonest or just stupid when you claimed you didn’t know about the crime? In all of these examples the same presumption occurs: we presume that one question is true and attempt to get the person to affirm it by answering a different question. The first example presumes that the person beats his wife in asking him how long he has been doing so. It does not give the individual the option of denying that he is beating his wife. The second example is similar—the child is never given the chance to deny that she stole any cookies. Any answer will be an admission of guilt. The third example is an interrogative form of bifurcation. The person is offered only two options, either of which makes him or her look bad. As you can imagine, the complex question is a favorite of lawyers, who often try to trick witnesses on the stand into admitting something that they would not admit if asked directly: Why did you wipe your fingerprints off the gun after using it? The way of handling a complex question is to question the question. Stop and ask yourself if there is more than one question being presented. Then take the time to separate and answer the questions individually. Do not get trapped. Fallacies of Relevance Our last group of fallacies both is the largest group and contains some of the most common fallacies. What binds this group together is that all of the fallacies employ premises that are irrelevant to the conclusion being proposed. They might appear relevant and are presented that way, but on close analysis the conclusion does not follow from the premises. Like many of the fallacies we have already encountered, these can be intentional or unintentional. Many times arguers are unaware of the irrelevancy of the premises to the conclusion. Sometimes they are aware of it and hope no one notices. There are many fallacies of relevance, but we will look at only a few well-known examples. Adhominem. In this fallacy the arguer attacks the opponent instead of the issue. Ad hominem is Latin for “against the
man.” The erroneous principle behind the fallacy is that bad persons cannot produce good arguments. Therefore, if I can show that an individual is bad in some sense, then I have given you a reason not to consider his argument because automatically it is a bad argument. However, the quality of the person giving an argument has nothing to do with the merit of his argument; it is irrelevant. There are three common forms of the ad hominem argument. First is the abusive form. In this form the personal character of the opponent is attacked: Senator Baker has argued that we should approve legislation in favor of protecting a woman’s right to choose to terminate her pregnancy. However, Baker is a left-leaning atheist who was recently caught in a scandal with his secretary. How can we take the arguments of such a man seriously? Dr. Wilson argues that there is strong evidence that Jesus rose from the dead and that the Gospel accounts of the resurrection are substantially reliable. However, isn’t she a member of the Pinewood Country Club, an organization known for its racist membership policies? Is she really the best person to be arguing about Jesus? The first argument directly attacks the character of Senator Baker by claiming that because of his beliefs and practices his argument is not worth listening to. Obviously, though, Baker may still offer a good argument regardless of his beliefs and lifestyle. They are irrelevant to the strength of his argument. The second example attacks Dr. Wilson indirectly by associating her with something distasteful and then uses that association to discredit her argument. But the fact that she belongs to a group that may have questionable practices is irrelevant to the argument she has produced. A second form of the ad hominem is the circumstantial form. In this version, the person’s motives rather than his character are attacked. If the position he is arguing for happens to benefit him personally, then, it is claimed, that should discredit his argument. Bill’s argument that Deuteronomy 14:26 should be interpreted as sanctioning drinking alcohol should be rejected. He just wants to justify his lifestyle of partying and drunkenness. This may be the motive for why Bill has argued for this interpretation of the passage. But even if that is true, it does not entail that his argument has no merit. Just because the conclusion of an argument personally benefits a person is no reason to discount it as a bad argument. The motives behind an argument are irrelevant to whether it is a good argument or not. Most of us argue for things that we strongly believe in and therefore could be accused of bias in favor of the conclusion we are advocating. But that does not mean that our argument is without merit. We must judge the argument on its own merits regardless of who is making the argument or the reason they might be making it. A final form of the ad hominem is the tu quoque (“you also”). The idea behind this fallacy is that the person making the argument is guilty of the practice she is arguing against, so her argument is invalid. When I was a young teenager I decided to try smoking cigarettes and was caught by my parents, who sat me down and lectured me about the dangers and detriments of smoking. It was hard to see them across the table, as I was blinded by all the smoke from the cigarettes they were puffing away on as they lectured me. Naturally my immediate response was, “Your arguments obviously fail—look at how much you smoke yourselves.” However, the fact that they did not follow their own advice does not mean that they did not have good arguments. We can all agree that we should practice what we preach, but the fact that we do not practice it does not mean that what we preach is wrong or invalid. The weakness of our will to do what we know is right does not discount good arguments that it is the right thing to do. If I were to argue for the sanctity of marriage and you were to discover that I had been involved in an affair, it does not discount my argument even though you could question whether I am the one who should be making it. It might make me inconsistent, but not my argument. Ad populum.This fallacy appeals to the idea that if a position is popular, then that constitutes positive evidence that it must be right. Ad populum is Latin for “appeal to the people.” The most common way this is done is by showing that a large number of people agree with a position and therefore you should
also. This is a favorite with advertisers: Four out of five Americans choose Zest soda pop over its leading competitor. Eighty percent of Americans can’t be wrong. Buy Zest today. The number of people who favor a product has nothing to do with whether you should buy it or not. This fallacy is also a favorite in political campaigns: Polls show that most Americans are overwhelmingly in favor of the president’s performance over the last four years. Reelect the president and keep America strong. Oftentimes a subtler version of this fallacy inverts the logic. Rather than appeal to the majority, it appeals to a select few. The idea is to appeal to our desire to be special and unique. Many of us are familiar with the advertisement “The few, the proud, the Marines.” This form of the fallacy appeals to our vanity and tries to convince us to agree with the conclusion because doing so will include us as members of an elite class of individuals. Not everyone can understand these complex arguments for my position. However, a few of you are bright enough to get this and will see the force of my conclusion. Mercedes-Benz. It’s not for everyone. A different type of the ad populum is the mob appeal. In this form of the fallacy, the crowd is whipped up into an emotional frenzy based on some noble ideal. The heightened emotions, along with group dynamics, carry the audience along. In all the turmoil they often stop listening and evaluating what is being said. This often occurs in large group meetings, such as political conventions or religious revivals, where a single individual is speaking. If the person speaking is on “our side,” we will tend to go along with the crowd and unreflectively agree with almost everything the speaker says. I have observed speakers in front of large crowds of college students presenting terrible arguments and advocating highly questionable notions and have watched as these crowds rise to their feet, cheering and applauding. Yet I know that if they were to calm down and reflect about what was being said, most would be very hesitant to agree with the speaker. There is some truth to Ibsen’s warning: the greatest enemy to the truth can be the majority. Red herring. In the days when fox hunting was common, one technique employed in training the hounds was to drag a red herring across a trail and attempt to throw them off the scent. That is what happens with this fallacy. The idea is to divert the attention of the listener by subtly changing the subject. As you can imagine, this is a favorite among politicians, many of whom exploit the approach, “Don’t answer the question that was asked; answer the question they should have asked.” Note how the technique might be used in a presidential debate: Moderator: Senator, you have been accused of waffling on the issue of illegal immigration. At one point you seemed to be in favor of tighter restrictions but recently seem to be open to an amnesty program for illegal aliens already present in this country. Can you clarify your position for us? Senator: Thank you for giving me the opportunity to do that. Let me just say that our country is the great melting pot of different cultures and nationalities. We have greatly benefited from the skills and talents of the many foreigners who have come to our shores, and we should welcome their innovation. If I am elected president I plan to establish educational programs for those who come to our great country seeking a new life in a land of great opportunity. This example shows how this fallacy often works. Notice how the subject is subtly changed from illegal immigration to the subject of the values and opportunities for any immigrants coming to the United States. The effective red herring will select a subject that is subtly related to the original, thereby avoiding detection. This is a fallacy of relevance because the new subject is irrelevant to the original topic under discussion. Straw man. The straw man fallacy is similar to the slippery slope and bifurcation in that it usually appeals to an extreme as part of its tactic, but it operates differently from those two fallacies. The fallacy occurs when one takes another’s argument, distorts it to an extreme and then proceeds to tear down the distortion in the belief that the arguer has torn down the original argument. The distortion is called a straw man because it is a false imitation of the original argument. Note the following examples: My opponent has argued for an increase of subsidies in the Medicare program.
What he is really arguing is for socialized medicine and the nationalization of medical care. However, this would destroy any incentive in the private sector to provide quality care. We would go from having the best medical care in the world to having the worst. Clearly my opponent’s arguments must be rejected. Christians teach that all people are sinners and are in need of God’s grace to get to heaven. However, the vast majority of people aren’t murderers, thieves or rapists. Therefore, Christians are wrong to condemn most people to hell. Both of these examples have distorted the original argument. In the first example, what was being proposed was an increase in Medicare. This was distorted into a more extreme position that the original arguer never intended. The distortion was then discredited. The original argument was neither addressed nor discredited. In the second example, the original argument is saying that sin keeps us from God. The arguer comments only about extreme sins and never addresses the issue of sin itself. In doing so he thinks he has defeated the original argument. It is easy to confuse the straw man with the red herring, as they both deal with replies to original arguments. To avoid such confusion, keep this distinction in mind: The red herring avoids the original argument by changing the subject. The straw man distorts the original argument to an extreme and then destroys the distortion. Appeal to pity. Our final fallacy is one that I encounter often. In fact, I have nicknamed it “the student’s fallacy” because I observe students committing this fallacy so frequently. It is called appeal to pity because, rather than argue on the merits of the issue itself, a person makes an irrelevant emotional appeal meant to rouse sympathy for the person involved, diverting attention away from the real issue. Here are some examples: I think you should pass this student on the final. I know she failed it badly and she really doesn’t have a good understanding of the material. But she studied so long last night. If she fails it will be impossible for her to pass the course and graduate next week. Her parents have already paid for plane tickets to come to the commencement, and they can’t get a refund. She is so ashamed and sorry she didn’t do better. She’s been in tears all day. Can’t you just give her the points? Your honor, I know my client is guilty of tax evasion. But he has been going through an extremely difficult time lately. He lost his job due to an injury, and his wife took the kids and left him. We need to find him not guilty and give him an opportunity to get back on his feet. How can you say assisted suicide is wrong? I have watched three loved ones slowly die of cancer. They suffered through excruciating pain as they slowly deteriorated over time. Jesus said, “Blessed are the merciful.” I think we need to heed his teaching. One can sympathize in all three of these situations, for they are all emotionally difficult. However, the argument being made in each is irrelevant to the issue at hand. In the first example (which is more common than you can even imagine), while we can feel sorry for the student, the fact is that grades are supposed to reflect the student’s understanding of the material in the course. Assuming the test is fair and well written, failing it informs us that the student does not have an adequate understanding of the material. The situation of failing the class, not graduating and the parents not being able to obtain a refund is irrelevant to the issue at hand, which is an adequate understanding of the material. In the second example, none of the aspects of the defendant’s life has anything to do with whether he is guilty of tax evasion. The purpose of the court is not to help him get his life together; it is to render a verdict concerning tax evasion. Finally, the question of the morality of assisted suicide is not settled by being merciful. It involves questions of justifiably intending to end a person’s life and the important question of a doctor’s role in helping someone do that. While not denying the emotionally gut-wrenching experience of watching a loved one suffer, we cannot allow emotions to take control in such situations. Such complex issues need rational, reflective consideration. Conclusion I stood there looking at the card in my hand. I laid it on the table, stepped back and continued to watch the magician perform sleight of hand. His performance was mesmerizing. After he finished and the crowd was dispersing, I asked him to tell me how he fooled me. He told me that
a magician never reveals his tricks. However, he could see how earnest I had become, and so he offered to teach me a simple vanishing coin trick. He told me never to perform the trick until I had practiced it enough to perform it flawlessly. He said that if I could master that trick, he would tell me where I could learn more. Many years later I learned how to do the three-card monte and have performed it over the years for friends. Sleight of hand taught me that, through practice, you can learn to master great abilities, including learning how to spot informal fallacies. I challenge you to read, listen and practice honing your ability not to be fooled. You will have no trouble finding examples, for, unlike street magicians, informal fallacies are all around us. Addendum Exercises Here is a list of the fallacies we covered in this chapter grouped together by type, followed by several exercises for each group. See whether you can identify any of the fallacies below. Fallacies of Weak Induction • Hasty generalization • Sweeping generalization • Weak analogy • False cause • Slippery slope 1. Third baseman Wade Boggs was so superstitious that he would eat chicken before each game and take batting practice at exactly 5:17 each evening before a night game. He ended up with a .328 career batting average, won five batting titles, collected more than 3,000 hits, played in twelve All-Star games, won a World Series and was inducted into the Baseball Hall of Fame on his first ballot. Following those superstitions really pays off. 2. Human beings have the ability to calculate numerical equations and process information, and they have basic rights. Computers can also calculate numerical equations and process information. Computers must have basic rights as well. 3. Our students are requesting that we reexamine our assessment policies. But if we begin down that road, where will it lead? Next they will insist we eliminate exams altogether. This will lead to the abolishment of our courses and programs. Soon the entire university process will be abolished. We must resist this movement by the students to destroy higher education. 4. She is the third student I have caught cheating this term. The obvious conclusion is that you just can’t trust any of these students anymore. 5. The Constitution guarantees freedom of speech. Therefore, there is nothing wrong with someone crying “Fire!” in a crowded movie theater. Fallacies of Ambiguity • Equivocation • Hypostatization • Amphiboly • Composition • Division 1. Every word in Lincoln’s “Gettysburg Address” is ordinary. Therefore his speech is ordinary. 2. It is greed that builds and improves the country’s economy. If greed is left alone to do his job, wealth accumulates and the whole country is better off. If greed is impaired, then thrift takes over, and she will stifle growth. Leave greed alone. He will be kind to you in the end. 3. The verdict rendered by the jury was reasonable and just. Therefore Erin, who was a member of the jury, is a reasonable and just human being. 4. Did you hear that Paul has a picture of Jeannette hidden in his locker? I wonder how he was able to get her to fit in such a small space. 5. How can you doubt the miracles of the Bible? Every day we witness the miracle of a new birth. Fallacies of Presumption • Begging the question • Bifurcation • Special pleading • Complex question 1. My sister really bugs me. She keeps going through my things and borrowing them without asking. The other day I found one of my sweaters in her drawer. 2. Philosophy instructors must be intelligent people because they wouldn’t be philosophy instructors if they weren’t intelligent. 3. How long have you been cheating in this class? 4. Either she knew everything that was going on, in which case she is a liar, or she was completely oblivious to what was going on around her, which makes her an idiot. 5. We better stock up with as much as we can, because the others will get here soon and you know how they hoard everything. Fallacies of Relevance • Ad hominem • Ad populum • Red herring • Straw man • Appeal to pity 1. Michael J. Fox has argued for an increase in funding for stem cell research. But Fox has Parkinson’s Disease and is only arguing for stem cell research so they will find a cure for him. Therefore, we should reject his arguments. 2. My opponent argues that teachers are doing a poor job educating our children on the basics these days. However, the real problem in our schools is student attitudes and behaviors.
Students are late to classes, show up in tattered jeans and T-shirts, and spend all their free time on Facebook and Twitter. They have no sense of self-respect and no discipline. 3. I think we should give the award for the best essay to Steve. He has had a rough time this year. He lost his mom to cancer, and his dad had to take on another job just to make ends meet. Steve tried out for the baseball team and didn’t make the cut. I know his essay may not be the best, but I think winning this award is just the boost he needs. 4. The workers have argued that we need to improve the ventilation system in the factory. However, there is no way we can afford a whole new air-conditioning system. It would mean all new duct work throughout the entire factory and three large new air conditioning units on the roof. The expense would be enormous. We will just have to reject the workers’ arguments. 5. Anyone with half a brain believes in evolution today. Therefore, you’d be wise to go along. Seven Analyzing Arguments I was a big fan of the television series House. For those unfamiliar with this series, it centered on one of the most iconic fictional characters ever created, Dr. Gregory House. House was an extremely intelligent medical doctor who headed the department of diagnostics at the fictional Princeton-Plainsboro Hospital. Every week he and his team would work on a particularly complex case to diagnose some rare disease exhibited by that week’s patient. House would use his superior analytic abilities to arrive at a conclusion and treatment just in time for the end credits. I often use House as an illustration in my bioethics class because he was not only extremely intelligent but also notoriously unethical. As a matter of fact, he was one of the most immoral reprobates ever to don a lab coat. He regularly lied to his patients and colleagues, bragging that he was justified because “everybody lies.” He constantly violated the rights of his patients with no regard for their beliefs or values, hurling insults at them as he treated them. His actions were often illegal and out of control. I describe him thus to my students and ask, “He’s a fascinating fictional character, but how many of you would want House as your doctor?” Amazingly, a significant number of them raise their hands. Why? It is because of those incredible analytic abilities. The students affirm the message of the show week after week: we will tolerate incredibly childish and decadent behavior to have someone who can analyze and solve problems in the way that House can. I was not surprised to learn that Gregory House was based in part on another fictional character known for his analytical abilities: Sherlock Holmes. Holmes too had an uncanny ability to observe and analyze a situation and arrive at a conclusion. When queried by Watson as to how he arrived at his conclusions, he would famously say, “Elementary, my dear Watson, I deduced it.” He would then explain step by step how he arrived at some remarkable conclusion. Watson would often respond that, as Holmes explained his steps, the reasoning was obvious. But before the explanation he was baffled by Holmes’s abilities. In A Study in Scarlet Holmes explains, “In solving a problem of this sort, the grand thing is to be able to reason backward. That is a very useful accomplishment, and a very easy one, but people do not practice it much.… There are fifty who can reason synthetically for one who can reason analytically.” Practice was the secret in becoming a good analyst. This last chapter is about analyzing arguments. I will approach our discussion from two perspectives. First I want to approach it from the perspective of constructing an argument, and then I want to offer a tactical approach to examining the arguments of others. With some practice, you can become as proficient as Holmes or maybe even House—sans the decadence. Let’s begin … the game is afoot. Elements of a Good Argument At some time or another all of us present arguments for ideas or beliefs that we hold. It may be in the formal setting of a paper or presentation for a class. You have been assigned a controversial topic and need to defend a particular position on it. It may or may not be your own position. Or the situation might be more casual, as in a conversation with some friends. You are talking over dinner and an issue comes up. Perhaps it is an ethical, political, theological or other social issue. There is some disagreement and debate over the topic. Perhaps you
have some strong beliefs, and those beliefs are being questioned by some person or persons. You attempt to defend your belief and recognize how inadequately prepared you are. So you later decide to do some research and prepare a better defense for the belief you hold. In either of these situations, you need to construct an argument. I would like to suggest nine elements that you should think through as you put your argument together. Although this is not meant to be a comprehensive list of the elements of a good argument, I believe it is a good start. Good reasoning. Not surprisingly, the first element of a good argument is that it has good reasoning in it. Good arguments conform to the laws of logic. This means they will not contain contradictions. They will also maintain the rules of valid inference, the rules that govern deductive syllogisms, such as “affirming the antecedent in modus ponens.” Good arguments avoid the informal fallacies we discussed in chapter six. This first element implies that you need to have an adequate understanding of these rules and fallacies. I encourage those of you who are planning careers in which arguing is a regular activity to consider taking a course or two in logic and critical thinking to sharpen your reasoning skills. Clarity. This second element cannot be stressed enough. Good arguments are clear, accurate and precise. You need first to be clear in your own mind of what exactly it is you are defending. You need to be clear about the structure of your reasoning and how the premises lead to the conclusion. Second, you need to clearly communicate your thoughts and ideas to others. This involves using appropriate language that accurately expresses your ideas. It might mean taking the time to define significant terms so that everyone understands exactly what you are saying. If you watch good debates, the participants will often start by defining terms. This avoids potential problems when the argument becomes complex and one participant might equivocate on the terms in use. Striving toward clarity also means avoiding using emotionally loaded language and clichés. Such language introduces obfuscation into the argument. Above all you want to avoid the two great enemies of good arguments: vagueness and ambiguity. Consistency and coherence. Consistency means that within a set of beliefs none of them contradicts the others. Within your arguments you may introduce a number of beliefs to support the premises employed in the argument. It is important that these beliefs are consistent with one another. Inconsistency is a sign of falsehood and introduces problems into the argument. Sometimes our beliefs are not really inconsistent, but they might appear so because they have been inadequately expressed. Not only do they need to be consistent, but also they need to be expressed in such a way that the consistency is apparent. However, consistency by itself is not enough. A good argument is more than a bunch of consistent beliefs. In good arguments, beliefs need to be related together, and that is the task of coherence. Coherence means that the beliefs relate together in a way that is mutually supportive. I believe that my life has meaning and purpose because Jesus loves me and he would not love a meaningless life. This is supported by my belief in God as an infinitely good and loving being, by my belief that Jesus is divine and by my belief that the Scriptures are substantially reliable in what they tell me about Jesus. Each of these beliefs is consistent and coherent with one another. Comprehensive. Good arguments take all of the relevant facts into account and attempt to address all the known problems. This element recognizes an epistemic limitation: we rarely, if ever, have complete knowledge about an issue. In fact, one of the reasons many issues are open to discussion and debate is due to the lack of data at our fingertips. In an ideal world we might have all knowledge and then there would be no disagreement. Needless to say, this is not an ideal world. That being said, we want to be as comprehensive as we can. Good arguments consider all known reasonable alternatives and arguments for a view and can account for them as part of the overall argument. This does not necessarily mean that every alternative needs to be presented and addressed in your argument. The context will often determine how much needs to be brought up. In formal settings, such as presenting a paper among your
peers, you will probably address more alternatives than in an informal conversation over coffee. However, a good argument should at least have an answer prepared for challenges and alternatives if raised. Orderly structure. Good arguments are structured well; they are mapped out and presented in a form where the reasoning is apparent. As of this writing I have been teaching for about thirty years. I have read and graded thousands of student papers, many of which have been very good, but many of which have had serious difficulties. The most common problems I encounter are structural issues. Some papers have been such a mess that it is almost impossible to find any coherence in the paper. Premises, supporting issues and conclusions are all jumbled and confused. Part of the problem is that many people write like they converse. Conversation tends to be serendipitous. It will often jump from topic to topic with little structure. Many student papers do the same. Good arguments have an apparent structure to them that makes them fairly easy to follow. There are a number of means to accomplishing good structure. Most arguments will take one of two basic approaches. They will either state the conclusion first followed by the premises, or they will state the premises and then follow with a “therefore” type of conclusion. Either of these is effective, though the first is more common in formal settings and the latter in casual settings. If the reasoning is complex, you might consider setting your premises apart by numbering them or employing some other designation. If the premises themselves need further support, offer it along with the premise as a subpoint. Make sure it is clear which subpoint goes with which premise, and avoid raising support for a premise much later on in the argument. In extremely complex arguments you may need to summarize your main premises at the end and relate them together in a formal arrangement like a syllogism. Fair use of evidence. Good arguments use evidence fairly and avoid suppressing evidence in favor of a particular position. We all want to present the case for our view in its best possible light. In the process of researching and developing our argument we may run into problems and evidence counter to the view we support. We might be tempted to ignore or suppress that evidence. Perhaps we even hope our opponent will be ignorant of this evidence and it will not come up in the process of presenting our argument. However, if our goal is to arrive at the truth, then it is our obligation to examine all the evidence and account for it from our perspective. Good arguments do not have the option of being selective toward the evidence they consider. It all needs to be laid out in the open and considered. If there is a serious problem for the view you are supporting, then you need to seek for a way to account for that evidence if you are going to continue to maintain that view. It may be serious enough that you will have to amend or even abandon your position. Perhaps you cannot find a way to resolve the problem, but the evidence for your position is strong enough that you can still maintain the view you have and will leave this problem unresolved for now with the hope of resolving it in the future. The one thing philosophy does not allow you to do is to ignore it or suppress it in hope that it will disappear. It will not, and it is likely to rear its ugly head when you least expect it. It is always better to acknowledge honestly evidence contrary to your own view and deal with it up front. An additional advantage is tactical: it will usually take the wind out of your opponent’s sail. Positive/negative approach. Tactically, this is the strongest approach to take in presenting an argument. Good arguments not only present positive evidence in favor of the view they are supporting. They also provide negative evidence toward the view they are opposing. This can be direct evidence against that view or in the form of problems with the evidence that view employs. I recently viewed a debate between Sam Harris and William Lane Craig on the question, Is the foundation for morality natural or supernatural? In Craig’s presentation of his case for the supernatural foundation for morality, he began by arguing in favor of his position and provided a number of reasons why he thought the existence of God accounts for objective moral obligations. However, he did not stop there. He then examined the case for naturalism and
explained why the reasons Harris offered do not adequately support his conclusion that naturalism can account for objective moral obligations. Tactically Craig’s argument was very strong. He was not just offering another view. He offered a superior one. If you offer an adequate defense for your own view without critiquing the other view, then the best you may be able to arrive at is a draw—both views may be equally plausible. However, if you can show that not only does your view have good evidence but also the opposing view is weak, then your argument is much stronger. Best explanation. Rarely does any one argument answer every problem. It is important to remember that few controversial issues have perfect solutions with no problems. Almost every solution has some problems. The goal is not to find the perfect solution but to arrive at one you can live with, to discover which view offers the best explanation with the least number of problems. For example, I believe Christian theism explains certain facts in the world better than naturalism, such as the existence and design in the universe as well as consciousness and the presence of absolute moral obligations. However, I also recognize that there are aspects of Christian theism that are problematic and difficult to explain, such as why God allows specific evils to occur in the world or why he often appears as silent. Despite these problems, I believe that naturalism is much more problematic than theism. Theism offers a better overall explanation than naturalism in explaining a number of aspects of the world we live in. What does it mean to offer a best explanation? First, the best explanation will have the largest explanatory scope. Explanatory scope considers the quantity of facts accounted for by an explanation. The more facts accounted for, the more likely an explanation is correct. Second, the best explanation will have superior explanatory power. The explanation that can be understood with the least amount of effort, vagueness and ambiguity has the best explanatory power. You should not have to force facts to make them fit with the explanation. A third aspect of a best explanation is plausibility. This has to do with the explanation fitting with our background knowledge. The explanation that is more plausible given the background knowledge we already have is better than the one that seems implausible in accordance with background knowledge. A fourth condition is that the best explanation is minimally ad hoc. Ad hoc means an explanation that is created for the situation at hand. It is usually an explanation that would not generally apply but is necessary for this particular situation. It often employs the use of creativity and imagination to arrive at an explanation beyond what the evidence tells us. Generally ad hoc evidence is not looked on favorably and is viewed as an act of desperation. Therefore the explanation that is less ad hoc is considered the better one. Finally, the best explanation will have the property of illumination. By illumination we mean the ability of an explanation to provide light on related areas besides the question at hand. Sometimes a best explanation not only will explain the particular question under consideration but also will address a host of related questions and issues. For example, the resurrection of Jesus does not just best explain the facts of reports of his appearances and the empty tomb, but also it supports his claims to deity and the other claims of the miraculous in his life. It is important to note that the best explanation or theory may not be perfect in these five elements. Sometimes we must settle for the best we have. Principle of simplicity. Good arguments are those that do not contain unnecessary assumptions and reasoning. This element of a good argument, also referred to as parsimony, is usually traced back to the late medieval philosopher William of Occam. Occam developed a principle that states: Entities should not multiplied without necessity. He believed that many medieval philosophers had speculated about the existence of entities and principles that were bloated and unnecessary in explaining the world. For Occam, an explanation was usually the best when it did not contain unnecessary assumptions and baggage. He used this principle to cut away all of those ideas that he believed were not necessary and muddied the waters. It came to be known as Occam’s razor. Although it is not exactly the same thing, today we often refer to
the principle of simplicity by another term, the “kiss” principle: keep it simple, stupid. There is much to be said for keeping ideas simple. In general a simpler explanation will often be the best one. However, you need to be careful in how you wield Occam’s razor. The fact is, many issues are often more complex than we initially give them credit for. Care must be taken that in our striving for the simplest explanation we do not become simplistic. We already live in a culture that continually attempts to boil down complex issues into thirty-second sound bites. Many issues are enormously complex and need serious thought and reflection. I often cannot answer many of the multifaceted and intricate problems of philosophy with a naive, one-dimensional, quick response. Some simpler explanations may end up subtracting entities that are, in fact, necessitated. So this principle needs to be balanced: Keep your explanation as simple as is necessary while realizing that even the simplest explanation may need to be quite extensive and difficult. Analyzing Arguments: Tactical Approach Along with producing arguments we also frequently encounter arguments from others. In fact, by sheer number, we encounter many more arguments than we create. Although we may not recognize them as such, arguments are thrust at us daily. We encounter them in the media through advertisements. Many of the movie and television programs we watch and the books we read are not just entertaining us but are also arguing for a particular point of view. Stories are the most subtle form of argumentation, as we are often not aware of the subliminal argument being made. If we are not careful, we might find ourselves affirming ideas that, if they were presented directly to us, we would never agree to. In this second part of the chapter I want to present a strategy for analyzing the arguments we encounter. Naturally this strategy is somewhat general, as there are many different kinds of arguments out there. I believe that if you follow the steps I offer here, you will be on your way to understanding and evaluating many of the arguments you will come across as you continue to develop the philosophical mindset. In order to accomplish our goal, we need a sample argument to analyze. I will use a fairly simple one to start with and then will suggest some others as we go through our steps. Here is our argument: Westminster College is the best small liberal arts college in the state. Their faculty is well prepared and professionally active. Also, the students come in with high scores on college aptitude tests, and most of them are successful in their professions after they graduate. Step 1: Distinguish the premises from the conclusion. As we have discussed, the conclusion is the point the argument is trying to prove, and the premises are the reasons being offered to support why we should believe the conclusion is true. In order to analyze and evaluate the argument, we need to know which of these is which. So the first task in analyzing any argument is to find the conclusion. Sometimes the conclusion is obvious, and sometimes it is not. Here are three tactics to help you find the less-than-obvious conclusion. First, look for indicator terms. These are words that appear before the conclusion and indicate that it is coming. The most common are therefore, thus, so, hence, accordingly and consequently. There are also premise indicator terms that let us know a premise is coming: since, because, for, in that, seeing that and given that. Many arguments, such as our argument above, do not employ indicator terms. Sometimes you can mentally insert them, and that might help to determine the conclusion. A second tactic is to remember that most of the time the conclusion is either the first or the last sentence in the argument. That is often a good place to start. Sometimes an arguer will place the conclusion somewhere in the middle of the argument, but this usually is not the case. A third tactic is to ask what is the main point of this argument. Try to see the inferential link between the premises and the conclusion. What is the main point the arguer is trying to make? It seems to be that Westminster College is the best small liberal arts college in the state. Everything else seems to be functioning to support that point. That is our conclusion. Step 2: Rewrite the argument in standard logical order. In order to analyze properly an argument it is helpful to write it out in a form in which the
reasoning is apparent. This is where we separate the premises from the conclusion and from each other so we can examine each individual part of the argument. It is common to list the premises first and the conclusion last. In performing this step we have to first ask another question: How many premises are there? You can often organize premises a number of ways. In analyzing our argument, I have had students who organized it into two premises (one about faculty and another about students), three premises (one about faculty and two about students) and four premises (two about faculty and two about students). Which one is correct? While there is not a definitively right answer to this question, we need to remember what our goal is: analysis. In general a good principle when you are analyzing is to break the item down to its smallest parts. Doing so with our argument yields four separate premises. This is also giving the strongest interpretation to the argument, which fulfills another important principle in analysis: give the author of the argument the benefit of interpreting the argument in the strongest way possible. An argument with four reasons in support of the conclusion is generally stronger than one with only two. Therefore, our argument can be rewritten: Faculty are well prepared. Faculty are professionally active. Students come in with high scores on college aptitude tests. Most students are successful in their professions after they graduate. Therefore, Westminster College is the best small liberal arts college in the state. Step 3: Do these premises support this conclusion? You might ask, “Why is this question next? Shouldn’t we first check out the premises and see whether they are true and then see whether they support that conclusion?” There are two reasons why this is the next question. First, remember our goal: we are trying to determine whether we have a good argument or not. At heart, a good argument is one where the conclusion follows from the premises. If the conclusion does not follow, then it does not matter whether the premises are true or not. There is also a practical reason for performing this step now: we can answer this question without doing any extra burdensome work. To check out the truthfulness of each of these premises will involve quite a bit of outside research. However, we can answer the question of inference without even leaving the room. It is right there in front of us. We may have to check out the premises later, but if the conclusion does not follow, then there would be no need—the argument fails. In asking this question first, we assume (for the moment) the premises are true, and we do not worry yet whether they are actually true or not. Answering this question means we need to look closely at the conclusion and ask ourselves, “What kind of evidence would support this conclusion?” and then see whether that is what is offered. Note that our argument claims that “Westminster College is the best small liberal arts college in the state.” It is not saying it is a good college, it is saying it is the best. There is a big difference. Best is a comparative term. It means “in comparison with other small liberal arts colleges.” When we look at the evidence being offered, we note that none of it compares Westminster College with other small liberal arts colleges. We would expect to see statements like “Their faculty are better prepared than faculty at other colleges” or “Students have higher scores than students at other colleges.” Instead we get a list of characteristics that might be considered good for a college, but that tells us nothing about Westminster being better than others colleges in these qualities. And that is the claim of the conclusion. Therefore, it looks like our argument, which might at first have appeared to be pretty good, has a fatal flaw—the premises do not support the conclusion. We will continue to use it for practice purposes. Step 4: Are the premises reliable and true? There are two reasons arguments fail: either the conclusion does not follow from the premises or the premises themselves are not true. If the conclusion follows from the premises, then that means that an argument is valid (in the deductive sense) or strong (in the inductive sense). However, validity or strength is only one part of a successful argument. In order for an argument to succeed, it also needs to be sound or cogent. That requires that we have good reason to believe the premises are in fact true and therefore
reliable for reaching the conclusion. When we were analyzing step 3 we assumed the premises were true. Now we need to check that out. This may involve some outside research on our part. Has any evidence been offered that leads me to believe that the faculty are well-prepared and professionally active or that students have received high scores on aptitude tests and are successful in their professions? What kind of evidence would that entail? Most likely we would want to see studies offering us statistics to show that these are in fact true. And if we are going to continue arguing that Westminster College is the best in the state, we are going to want to compare these statistics with statistics from other small liberal arts colleges in the state and see which is superior. We tend to be reticent in challenging arguers on their evidence, but it is not improper to request such additional supporting evidence. It is not uncommon for arguers to inflate claims to make their evidence sound better than it usually is. Thus, it is quite appropriate to assume that they have these statistics on hand to back up their claims and they should be able to produce them with little effort. However, we can evaluate the premises on another level that does not require sifting through studies, and that takes us to step 5. Step 5: Is the language definite and clear? Is there evidence of loaded language? One of the most important lessons I have learned in studying philosophy is the importance of paying attention to the language in which arguments are expressed. We are often subtly manipulated into affirming or rejecting ideas by the language in which those ideas are presented to us. Certain fields, such as advertising and marketing, are expert at employing language to spin an idea in the direction they want the audience to hear or read. Therefore it is extremely important to examine carefully the language in which claims are made to see whether it is accurate, precise and clear. As we look at the premises and conclusion in our argument, is terminology present that needs clarification and definition? We might want a clear definition of “small liberal arts” college. What criteria are employed to designate which colleges are a member of this group and which are not? How about the terminology in the premises? We might ask what exactly it means for faculty to be well-prepared. Do they all have minimal qualifications that allow them to teach, or do they have advanced and terminal degrees? What is meant by “professionally active”? Do they only teach classes, or are they published in peer-reviewed journals and regularly attend and read papers at conferences in their field? We can ask similar questions about the students. What is a “high score” on a college aptitude test? Is this test, which is an entrance exam, a good measure of the quality of the college, or would a better test be the comprehensive exams taken after they complete their studies at the college? When it is claimed that students are “successful in their professions after they graduate,” is the claim being made that they are working in the field in which they are trained, or does it mean they are good at whatever job they got? The vagueness of these claims leads us to believe this argument probably came from a marketing brochure written to recruit students to Westminster College. Recruiting brochures often intentionally employ vague language in order to make claims that are untestable. If someone claims a university is “the world’s most exciting university,” what possible means can be devised to test such a claim? The warning here is clear. You should carefully note the language used in an argument and ask, “Is it clear, or do I have questions?” The next three steps concern three of the most common forms of arguing: arguing by example, arguing by authority and causal arguments. Step 6: Consider arguing by example. It is common when arguing to use examples as evidence to support your conclusion: Richard Nixon will go down in history as our most incompetent president. Look at how badly he bungled the Watergate affair. If he had admitted his wrongdoing, he probably would have survived the crisis with little damage. A number of factors need to be considered when you argue by example. First, you normally cannot arrive at a conclusion on the basis of one example. One example could be atypical, a mere anomaly. In the argument above, it may be that Nixon bungled Watergate but handled
most other aspects of his administration extremely well. He was president for almost six years and was involved in a number of policy decisions. To take one instance from his presidency and reach a conclusion is to be guilty of the fallacy of hasty generalization. A second factor to consider: Are the examples employed representative of the point you are making? I think we have good reason to believe the conservative Republican candidate will win the presidential election. A poll of Liberty University students on the East coast and the citizens of Orange County, California, on the West coast confirm an overwhelming majority of voters in his favor. The problem with this example is that while these polls may support the conclusion, the samples polled are known for being predominantly populated with politically conservative individuals. They are hardly representative of the whole country voting for the president. In order for examples to work as evidence they need to be broadly representative. Another factor to consider in evaluating an argument based on examples is the presence of possible counterexamples. A counterexample is an example that refutes the ones that have been suggested in support of the conclusion. Counterexamples have the function of weakening an argument by showing that the conclusion does not necessarily follow. Note the following: The Peloponnesian War was caused by the Athenians’ desire to dominate Greece. The Napoleonic Wars were caused by Napoleon’s desire to dominate Europe. World War II was caused by the fascists’ desire also to dominate Europe. Thus all wars are caused by the desire for territorial domination. The conclusion of this argument is universal: “All wars are caused by the desire for territorial domination.” If you wanted to challenge this conclusion, you could offer a counterexample by suggesting a war that was not caused by the desire for territorial domination. The American Civil War and the French Revolution would be excellent counterexamples, as they seem to be more about ideas, such as freedom, rights and justice, than about territory. In the earlier example of Richard Nixon, you could point to his foreign policy decisions, which many argue were some of the best of the twentieth century, as counterexamples to the charge of his presidency being the most incompetent. As you can see from these examples, the use of the counterexample method works best when the argument makes universal and extravagant claims. Step 7: Consider argument by authority. None of us is an expert in everything, and so we often have to rely on others to provide information that we may use as evidence in an argument. We call this argument by authority. At least part of the reason why I support a particular conclusion may be that experts who are intimately acquainted with the issue have weighed in and offered their authoritative opinion. Given their expertise, we usually give such testimony a lot of evidential weight. Therefore, if relevant, it is appropriate to quote or cite an expert as support for a position you wish to defend. Consumer Reports tested the new 2012 model of the Toyota Camry Hybrid LE and found that it gets 43 MPG in the city. Therefore we can conclude that it gets great gas mileage in the city. There are a number of factors to consider when arguing by authority. First, it is important that the authority being quoted is a bona fide and informed authority on the issue under consideration. Just because one might be considered an authority in one area does make one an authority in all areas. Consumer Reports is a recognized authority in examining and evaluating consumer products. Therefore the argument above is a good one. However, note the following: All this talk of global warming is nonsense. My pastor spoke on it this past Sunday. He said these kinds of climate fluctuations have been going on for centuries and we have nothing to worry about. He ought to know what he is talking about—he has a graduate degree from one of the top seminaries in the country and has published a number of books. I have no doubt that this pastor is knowledgeable about a number of areas such as theology and Bible. However, that does not make him an expert on shifting meteorology. A closely related fallacy is individuals who are experts in an adjacent field, but not necessarily an expert on the question under consideration. I recently read a book proposing that the stories of Jesus were taken
from ancient Egyptian texts that relate the story of Isis, Osiris and their son Horus. The author quoted as her primary sources experts in Egyptology and Egyptian religion. These authors may have expertise in Egyptian history and religion, but they are not experts on the development of Christian beliefs. The experts in that field almost unanimously refute any claims of a contributing relationship between Jesus and Horus. Another factor in employing an authority concerns the problem of conflicting authorities. Even authorities often disagree with one another. If you are going to argue by authority, you should attempt to arrive at a consensus of authorities. In many cases this is possible. However, often a consensus is not to be, and it would be disingenuous to claim one. We should avoid claiming a consensus without having done the required research to support such a claim. I have often heard the phrase “the majority of experts say …” or “experts say …” with little or no evidence offered to support the claim. Similarly it should be noted that merely claiming an expert does not necessarily settle an issue. Authoritative expertise carries a significant amount of weight, but experts can be wrong. Most philosophers agree that there are some areas where there is not an expert. Ethics, politics and religion are three areas where it is usually recognized that quoting an expert does little to resolve an issue. While there can be experts about these topics, it is generally recognized that there are no experts who offer definitive answers on these questions. Finally, you should remember that ad hominem attacks do not discredit an expert. We are valuing the individual’s expertise on a specific issue. We are not evaluating his or her personal beliefs, characteristics or actions. Step 8: Consider causal arguments. We often argue about why an event occurred by pointing back to its cause. For example: The stock market crash of 1929 was the result of a perfect storm of social and economic events. An agricultural recession along with the speculative bubble of prosperity caused an abnormal increase in debt. These factors coupled with overvalued shares and weakness in the bank system caused the inevitable bubble to burst and the crash to occur. Arguments like the one above are often found in social, medical, historical and physical sciences. Causal arguments are common, but they can be more complicated than they might initially appear. One factor that will help to strengthen a causal argument is if the argument explains how the cause led to the event. Merely asserting a causal connection is usually not enough to make the argument work and lays you open to the charge of a false cause. You do not need to provide every detail to justify a causal connection, but you should offer some of the elements to show how one event caused another event to occur. In the argument above, enough detail is given to show how the different social and economic elements worked together to cause the 1929 stock market crash. The above example illustrates another important element in causal arguments. Social events are often the result of multifaceted causes intricately connected together. Rarely is it just one thing, and care needs to be taken to not oversimplify a cause. SAT scores have dropped to a new low recently. The reason is clear: teachers just aren’t doing their jobs anymore. Although it is tempting to identify one cause for an event and thereby arrive at a supposed quick fix, reality is usually more complicated than that. The reason SAT scores might drop is probably due to a host of factors, one of which may be that teachers are not functioning up to speed. This is an oversimplification. Many events have more than one possible cause. Sometimes it is not so much finding a cause as it is finding the most likely cause for an event. When I was in middle school I heard a story of a ghost that wandered the tracks near where I lived. The story was that many years before a railroad worker fell out of a train and was killed. Now he eternally wanders along the tracks waving his red lantern. One evening some friends and I went to check it out and, sure enough, looking down the tracks we would see a red light suddenly appear and wave across the tracks and then disappear. Now it is broadly possible that the explanation for the effect was the ghost of a railroad worker. However, another explanation was possible. What we were seeing was an intersection
further down the tracks where cars drove across the tracks at an angle such that all we could see were their red tail lights. It was so far away that we could not hear the cars and could only make out the lights. Which explanation is more likely? It seems without even testing the two that the second explanation is obvious. But why should I automatically say that? When it comes to more than one cause, and we are not able to test them, a good general principle is to embrace the cause that goes with our established beliefs and experiences. As a Christian I am open to supernatural causes for events, but in general I do not jump to a supernatural explanation for a cause unless I have strong evidence that the supernatural is involved. Finally, it is important that you can show that two events are, in fact, causally connected. Sometimes random events occur that are coincidental and not causally related. Be careful not to jump to conclusions without sufficient evidence that a causal connection is involved, or you might end up affirming an argument like the following: Bread is bad for you. Why? Consider the following facts: More than 98 percent of convicted felons are bread users. Half of all children who grow up in bread-consuming households score below average on standardized tests. In the eighteenth century, a time when bread was baked primarily in homes, life expectancy was less than fifty, and infant mortality rates were high. More than 90 percent of violent crimes take place within twenty-four hours of eating bread. The conclusion is obvious: Stop eating bread. Step 9: Check for fallacies. The final step in evaluating an argument is to look for any formal or informal fallacies within the argument. This requires that you have a good understanding of logic and of the informal fallacies we discussed in the previous chapter. In general the main thing you are looking for is a non sequitur. Does the conclusion follow from the premise? If not, identify the fallacy being committed. This is not easy and takes practice. However, if you work hard at it you can become an expert analyst. By doing so, you will live a fuller and richer life and will become a more effective disciple of Jesus Christ. Epilogue Seven Virtues of a Christian Philosopher I would be remiss if I were to write a book introducing philosophy to Christians and did not take some space to discuss those qualities that I believe make one a good Christian philosopher. Philosophy is about more than examining and evaluating arguments or gaining knowledge about abstract concepts. In the first chapter I contrasted a job with an occupational vocation and stated that philosophy is more like the latter. Developing the philosophical mindset is a way of life, a process of becoming a particular kind of person. Perhaps the best way to express this is in the language of virtues. The concept of virtue has a long and honored tradition in Western philosophy. From the beginning many philosophers recognized that our actions and the activities we pursue are largely dependent on the character qualities that are embedded into us from the earliest days of our childhood. These character qualities are called virtues and vices. A virtue is a trained behavioral disposition to act in a good or righteous manner, and a vice is its opposite. Virtues and vices are analogous to good and bad habits. If you think of a habit, it is something that is built into your personality through practice over time such that you may rarely think of it but regularly act on it. Virtues are honorable characteristics that become a part of who we are. They are often so much a part of our being and personality that we may be associated with them: “He is a man of integrity.” Traditionally virtues have been divided into two categories: moral virtues, such as kindness, humility or honesty; and intellectual virtues, such as wisdom, studiousness or inquisitiveness. Although there is no one definitive list of virtues, historically a set of moral virtues developed over time that came to be known as the seven cardinal virtues: prudence, temperance, fortitude, justice, faith, hope and love. It was believed that all other virtues flowed from these seven. In like manner, I want to propose seven virtues of a Christian philosopher. As I do so, let me first note that virtues do not stand in isolation. They are teleological and communal. By teleological we mean that they have a goal or purpose. Aristotle suggested that the goal for the virtues was the achievement of eudaimonia, or the good life. By
communal, we mean that the virtues are formed within a community of individuals with a shared conception of what that good life is. Christians form such a community, and I would like to suggest that the ultimate goal for Christians in general, and for Christian philosophers in particular, is to glorify God. The Westminster Larger Catechism says it best: “Man’s chief end is to glorify God and to enjoy him forever.” Therefore the virtues of the Christian philosopher are those that glorify God. What might these be? Love of truth.Christian philosophers have an unquenchable love of the truth. It is this love of truth that drives an undying intellectual curiosity to know and understand the deep things of God and of his creation. This appetite for truth is insatiable: the more we know, the more we desire to know. The more educated we become, the more we realize how little we know, and hence the appetite continues to grow. We read, reflect, discuss and read more in an effort to understand. Like any virtue, an excess of the desire to know can become the vice of vicious curiosity, where our desire to know so controls us that we neglect other moral and epistemic duties. The history of medical research is littered with stories of abuses by well-meaning researchers who trampled on the rights and values of individuals in their quest for knowledge. However, of greater concern is the opposite vice that has become rampant in modern Christian evangelicalism: anti-intellectualism. Some are almost proud of their lack of knowledge. Such an attitude does not bring glory to God, for people are not loving the Lord with their minds when they refuse to use that mind to the best of their ability. Os Guinness writes, At root, evangelical anti-intellectualism is both a scandal and a sin. It is a scandal in the sense of being an offense and a stumbling block that needlessly hinders serious people from considering the Christian faith and coming to Christ. It is a sin because it is a refusal, contrary to the first of Jesus’ two great commandments, to love the Lord our God with our minds. Anti-intellectualism is quite simply a sin. Evangelicals must address it as such, beyond all excuses, evasions, or rationalizations of false piety. The reasons for this spirit of anti-intellectualism are varied: laziness, bad theology and bad exegesis are some. Many Christians are afraid of the truth. They fear that it will hinder their faith and cause doubt. However, God is the author of all truth, and all truth is God’s truth. If your faith is not true, then why believe it? And if it is true, then there is no fear in questioning and examining it. Christian philosophers embrace the search for truth. Diligence. There is no denying that philosophy is hard work. It often takes many hours of reading and reflecting on complex ideas. It takes a significant amount of effort to construct an argument or to understand the structure of a problem. I often find that after a few hours of reading and writing about a difficult philosophical work that I am as tired as if I had been digging a trench in my backyard. So the virtue of diligence is necessary in order to push through and do the work that philosophical thinking requires. Diligence is the idea of persistent and continuous industry to accomplish a task. It is the virtue of not quitting, even, and especially, when the desire to quit is overwhelming. The opposite vice is laziness. We live in a day where we are regularly tempted to do only what minimally needs to be done. I often see this in classes. Many students are concerned more with getting a grade than with getting an education. Such a minimal goal provides fertile ground for a “doing the least I can do to get by” attitude. Because Christian philosophers love truth, they are willing to do the hard work necessary to obtain it; hence the need for diligence. Intellectual honesty. In his book on virtue epistemology, Jay Wood says, “Like so much of the virtuous life, seeking truth appropriately is a matter of seeking in the right way, for the right reason, using for the right methods and for the right purposes.” It would not make sense to strive to find the truth in order to glorify God and to do so dishonestly. Honesty involves the means and methods we employ in our search, as well as the results. Many of us passionately hold on to our beliefs with firm commitments. Such passion might tempt us to skew our research and evidence in favor of the direction we want it to go, rather than letting it point us in the direction of what is true. It was Antony Flew’s
lifelong motto of “following the evidence wherever it leads” that led to his conversion to theism late in life. It is easy to be blinded by our commitments and lose sight of our goal of finding the truth. However, any view that is arrived at through dishonest means is not going to provide us with truth and is not honoring to God, no matter how much we think it might be. I have seen good, intelligent people become so blinded as to use dishonest means to obtain what they sincerely believe is true. I once listened to a lecture by a Christian scientist. He related a story about visiting a museum that had shown a short film about evolution. The scientist noted what he thought were a number of serious problems in the presentation and asked to purchase a copy of the film to show his students. The museum staff explained that the film was not available for purchase or reproduction. The scientist then told us how he took his camcorder into the museum theater and illegally videotaped a copy of the film that he regularly shows in class. His zeal to teach the truth blinded him to the immoral and illegal actions he performed. God is not glorified when we attempt to teach truth through deception. We live in a culture in which the maxim “it’s easier to get forgiveness than permission” has become the new standard for morality. Christian philosophers are honest in how they obtain their data and honestly report the data they obtain. Fairness and respect. Christian philosophers treat others fairly and with respect. This virtue is in short supply among many Christians today. We live in a world of partisan politics where a white hat/black hat mentally has become all too pervasive. We demonize anyone who is not on our side of an issue. All who claim to be Christians are our friends and supporters, and all who claim otherwise are “the enemy.” Many are deluded into thinking that our friends can say and do no wrong and the enemy can say and do no right. Christian philosophers are acutely aware that this is not an accurate reflection of reality and is an attitude that does not glorify God. Those who hold beliefs that are different from ours and argue for those beliefs are not the enemy. Many of them are philosophers and thinkers who, like us, are on a journey to discover the truth. We might disagree, but we can still respect them for the work they do and treat them in a fair and equitable manner. Christian philosophers do not have a problem with disagreement. They mutually respect men and women of all beliefs and ideas. In fact, many of my friends are individuals (both Christians and non-Christians) with whom I disagree on a number of issues. Yet I respect them because they are good thinkers. Intellectual fortitude. Fortitude is a kind of courage, but it is different from bravery. Fortitude is the virtue that supports us when we need to overcome obstacles that arise in our journey. Think of the people who settled the West. They knew they would encounter incredible difficulties along the way: forging raging rivers, crossing endless deserts and scaling the tallest peaks. One can imagine the fear they faced as they set out on the journey. Fortitude is what got them through. Fortitude is not the absence of fear. It is working through our fears to achieve a goal. Christian philosophers often face a difficult journey, especially in a day when secularism and naturalism dominate our institutions of higher learning. They know that the beliefs they often defend are not popular in academia. The pressure to give in or to back off on one’s beliefs can be enormous. Intellectual fortitude is a necessary virtue to maintain the faith in increasing opposition, for it is not easy to promote an unpopular view. I recently observed a Christian thinker suggest a view that was unpopular among many Christians. Though he knew it would be unpopular, he believes he is right and produced good arguments for the view. It was fascinating to observe as he faced tremendous hostility and resistance from many, some of whom claimed to be his friends and allies. He lost his job, his reputation suffered, and many speaking engagements were rescinded because of the unpopular position he took. It would have been easy for him to recant his view. But he believes he is right. Whether he is or not, I admire his intellectual fortitude in standing by his principles. Such fortitude glorifies God. Epistemic humility. Epistemic humility is the virtue of recognizing that we are limited in our knowledge and in our ability to
know. Recognizing this limitation is a key to growing and learning. In a desire to convey confidence in their beliefs, many Christians make claims that go far beyond what the evidence allows. They become arrogant and proud in their delusion of how much they think they know. Such individuals need a healthy dose of epistemic humility. They need to recognize that most problems are more complex than they assume and that many intelligent and sincere people whose views differ from their own offer very good arguments in support of those views. Epistemically humble Christian philosophers offer arguments unpretentiously, recognizing their own fallibility, and are open to being shown where they might be wrong in their reasoning. They know the difference between views of which they can be confident and those they hold with reservation. Above all, they know the difference between confidence and arrogance and avoid the latter. When they encounter views of those with whom they disagree, they listen respectfully and seek to understand. They look for areas of commonality and respectfully note differences of opinion. The need for epistemic humility brings up a special group worth commenting on: the novice philosopher. In the thirty years that I have been teaching philosophy, I have noticed how we philosophy teachers are in constant danger of creating philosophical Frankensteins: students who pick up a little philosophy, perhaps taking a course or two, and become arrogant, elitist little monsters. I have observed the haughty attitudes of these students toward their fellow students who do not understand the wealth of knowledge they have obtained. I am reminded of what one of my professors told me many years ago: the more you understand a subject, the more humble you become as you realize how enormous it is and how little you are. First Corinthians 8:1 (KJV) says, “Knowledge puffeth up.” I would remind my novice students to maintain epistemic humility and to remember that they are not that far from where their fellow students are. We are all on this journey together. None of us has the right to think we have arrived. Teachableness. The last virtue follows nicely on the tail of epistemic humility. Good Christian philosophers are teachable. They are open to learning from others. This involves all of the former virtues. To be teachable means that, out of love for truth, you are willing to place yourself under the guidance of another, which involves epistemic humility. It is to honestly admit a certain amount of ignorance, which takes courage, and to be willing to listen and to learn, even from those with whom we might find some disagreement, which takes respect. It involves hard work in understanding and communicating with the teacher, which takes diligence. Jesus looked for disciples who were teachable. The Christian philosopher needs to model this virtue. You might say, “Yes, this is all well and good. But I am not going to be a philosopher by trade. I have another vocation in mind.” If you think that, then you have missed the point of this book, for all Christians are called to be philosophers. Developing the philosophical mindset is one of the most important ways we understand God and his world. Through this he is glorified. Soli gloria Deo.Mark Foreman, Prelude to Philosophy: An Introduction for Christians(InterVarsity Press Academic, 2017), 121–197.