G.E. Moore identified the following as the fundamental contradiction of egoism (Principia Ethica, section 59): The egoist says that each person ought rationally to hold, “My own happiness is the sole good”: “What egoism holds, therefore, is that each man’s happiness is the sole good – that a number of different things are each of them the only good thing there is – an absolute contradiction!” (emphasis Moore’s).
I’d assume the egoist’s response is that this misstates his doctrine. Obviously, if the egoist thought that each person’s happiness is the sole good then he’d be committed to the contradictory view that: (i) A’s happiness is the sole good (so B’s happiness is not a good) & (ii) B’s happiness is the sole good (so A’s happiness is not a good).
In fact, egoism is the view that each person’s happiness [or flourishing or whatever] is the sole good for him. The egoist is thus only committed to the view that A’s happiness is the sole good for A, which is compatible with B’s happiness is the sole good for B.
Huemer doesn’t address himself to this move, but Thomas Nagel has a famous argument against this conception of egoism, which is very nicely explicated, and confuted, in Stephen Darwall’s Nagel’s Argument for Altruism. I draw on that reconstruction in the next three posts.