Psychological egoism is a theory that suggests that humans are always motivated by self-interest, even in what seem to be acts of altruism. The theory claims that, when people choose to help others, they do so ultimately because of the personal benefits that they themselves stand to gain, directly or indirectly, from doing so. Psychological egoism is a non-normative or descriptive theory in that it only makes claims about how things are and not how they ought to be. The theory is, however, related to several other normative forms of egoism, such as ethical egoism and rational egoism. The following essay seeks to determine the plausibility of psychological egoism as a theory of ethics by presenting possible arguments for and against it.
In Elements of Moral Philosophy, Rachels defines psychological egoism as the view that “all men are selfish in everything that they do, that is, that the only motive from which anyone ever acts is self-interest” In dealing with psychological egoism, Rachels presents the rational view that people act unselfishly all the time, and offers the hypothetical example of a man named Smith who gives up a trip to the country to stay behind and help a friend with his studies. Such an act would certainly appear unselfish, but there are two arguments that the psychological egoist may put forward to argue that this is not the case.
The first argument in favour of psychological egoism is that because people always do what they most want to do (act on their