Mackie's Argument Between Queerness And Relativity

Moral realism is the common belief that there are objective moral values. David Brink states that a “fairly clear core element in moral realism” is that “(1) there are moral facts or truths, and (2) these facts or truths are independent of the evidence for them”. (1) and (2) are not sufficient conditions for all forms of moral realism, according to Brink, but he believes they are necessary, so rejecting them means rejecting moral realism. This is what JL Mackie intends to do in his arguments from queerness and relativity. The argument from queerness is more convincing than the argument from relativity, but in the end neither of Mackie’s arguments give us good enough reasons not to be moral realists.
Mackie’s argument from relativity asserts

There are people who believe that the Earth is flat, and people who believe that it is round. Their beliefs clashing does not cause there to be no objective truth about the shape of the Earth. Likewise, the Greeks and Callatians disagree on a moral issue but there could still be an objective moral fact about how you are supposed to deal with dead bodies. Overall, therefore, Mackie’s argument from relativity is fairly weak.
Mackie’s argument from queerness goes as follows. It consists of two different arguments, a metaphysical one and an epistemological one. Both arguments conclude that moral realism entails the existence of things that are incredibly implausible. Therefore moral realism is itself implausible. First I will look at the metaphysical argument.
The metaphysical argument from queerness is based on the idea that moral properties are “of a very strange sort, utterly different from anything else in the universe”. The supposedly strange thing about moral properties is that they are action guiding, or imperatives. By virtue of moral facts existing, they have normative consequences that determine how people ought to act. There are no other natural facts that compel people in this way, and therefore moral facts are unlike other natural facts. So moral claims are in their own metaphysical category, which is a strange

He argues that we come to conclusions about the truth of both moral and nonmoral facts by assuming a theory, and then observationally testing our theories. To use his example, we might have the moral belief that Zenobia is a good person, and independently theorise that good people keep their promises. From this we will develop the observational prediction that Zenobia will keep her promises. So our faculties for perceiving moral facts operate in the same way as our faculties for perceiving nonmoral facts, and so moral perception is not actually