 The remainder of this essay will set aside these unorthodox alternatives to the common sense metaphysical framework that we normally presuppose when we think about self-interested and altruistic motives. It would take us too far afield to examine them. We will continue to make these assumptions: First, a single individual human being persists over time from birth to death, even when the mental life of that individual undergoes many changes. Second, there is someone one is referring to when one talks about oneself, even though there is no object called the “self” that we detect introspectively. And the fact that we do not encounter such an object by introspection is no reason to doubt the validity of the distinction made between oneself and others. Third, although certain things (arms, legs, noses, etc.) are by their very nature parts of a whole, no human being is by nature a part in that same way. Rejecting these ideas, we will continue to assume, with common sense, that for each human being there is such a thing as what is good for that human being; and that the questions, “what is good for me?”, “what is good for that other individual, who is not me?” are different questions. Accordingly, it is one thing for a reason to be self-interested, and another for it to be altruistic (although of course one and the same act can be supported by both kinds of reasons).