@Ruthless Logic,
1.1Human actions may be the result of choice or of compulsion.
1.1a If we understand by compulsion a natural and universal enforcement of selfishness, then we are presenting a moral interpretation of nature.This forces us to say that
despite appearances and autobiographical statements to the contrary, there is a "real" natural compulsion that actually was the cause of an action we commonly call altruistic, and this "real" cause was something called "selfishness." And this interpretation supposes that all actions (in the animal world, in the human world) have only ONE cause; one could as easily imagine a nature that would
also include group interest (preservation of the species, "the good of the many outweighs the good of the one").
1.b Now if the action was caused by choice, then it must be shown that the choice was motivated by self-interest and self-interest alone, and clear criteria must be provided. Moreover, it must be shown that an individual actually
knows what action is in his self-interest;since, if he acted wrongly or mistakenly, then it would be difficult to assert that
all actions were motivated by self-interest in an objective sense. For we would have to say that the person acted in what he assumed was in his self-interest, but wasn't
really, which would leave open the possibility that he acted for another reason.
1.b1 The argument supposes that human actions are the result of a choice about ONE end, and seems by its reduction, to ignore the possibility that a choice can be influenced by a whole hierarchy of ends, goals, or imperatives and that these can vary from one person to the next, and from one time to another.
1.b2 If we ask what evidence can be brought to show that a person always chooses his self-interest, then it must come from the actor himself, or our interpretation of it, for we cannot have intimate knowledge of the person himself. Yet we have many instances in which a person reports that he acted just for the opposite reasons, and we have no reason to believe he was lying about it. Again, we have a conception that some acts are not selfish, and have words to describe them (such as altruism), and do so on many occasions. It would be a curious position to say that both the actor and the spectator were both incorrect in their understanding of the action, and that what REALLY caused it was "self-interest," for then we end up with absolutely no criteria for establishing the REAL cause in the cases of choices as well as compulsion.
In both cases, it seems we are left with is an assertion, and little more, that all actions are
secretly determined by self-interest. One could easily argue in the same fashion, that all actions are determined by humours or invisible gremlins or the gods themselves.