Some time ago, a debate raged across Catallarchy and Crooked Timber about whether psychological egoism was true. A standard objection to the doctrine is that there is no conceivable action which couldn't be ultimatle selfish, thus it is simply a tautology, akin to "a triangle is a 3 sided figure." I think this objection fails because there is an action which is inconsistent with psychological egoism.
Imagine a man who is on the verge of suicide. He literally has a cocked and loaded gun in his mouth with his finger on the trigger. As he begins to squeeze the trigger, he realizes that he has no life insurance policy, has racked up $20,000 in debt, and would leave the entire mess to his wife if he killed himself. Out of concern for his wife, he takes the gun out of his mouth and decides to continue living.
The psychological egoist has a major problem with this thought experiment because it doesn't seem as if the man could possibly be acting out of his own self interest. His wife's predicament should play no role in his decision if he is an egoist. Even if he would feel guilty for hurting his wife or acting immorally, he can't feel these feelings if he is dead. If death is better than living before the realization, then death must be better after the realization.
One could object that he is worried about his potential afterlife. Realizing that hurting his wife could land him in hell, the man might be avoiding the lesser of two evils. This objection fails, however, because suicide could land him in hell. If the man was worried about going to hell, he wouldn't have tried to commit suicide in the first place.
The interesting thing about this thought experiment is that it isn't so much a thought experiment as history. The man is still alive and a friend of my adviser, who told me the story earlier today (minor details have been changed), which means that psychological egoism must be false. Or not, any objections? Comments?