From here, I will sketch my own ideas about psychological egoism before going to the of Feinberg’s objections.
Psychological egoism merely says that we, as human beings, always do what is initially better for us. Actually, it means that we never act the way out of our best interest or what we are convinced to be so. The most controversial item of defending psychological egoism is the following: even though people can find pleasing to do what they do, can we state that these people are motivated only by the pleasure they get doing what they do?
Nothingstanding to the complaint that psychological egoists are able to make any fact fit their theory, I am sure that the theory of psychological egoism itself can be proven in practice. And the proof is hidden in the single question, "Why?"
Take any action which one can dare to call altruistic, i.e. it turns up that the action in question is being done out of any motivation, and this is already another story. Now, why do you think the person did take that action? It seems to be quite clear to me that the motivating element that causes a person to take any action, altruistic in this case, must be the pleasure he gains from executing that “altruistic” act. The reasons why I believe in this are mostly intuitive and are based on the fact that I fail to find a reason for a person to take any actions without foreseeing some sort of pleasure from taking this very action. Thus, the answer for our “Why” question at the end goes down to one of the three following reasons:
1) it gives him positive emotions 2) he has strong belief that it will eventually make him feel good, or maybe 3) it enables him to avoid some form of displeasure and dissatisfaction (which is, in fact, just one more way to say that it makes him feel pleased and the action he chooses to take will always be chosen just because it is really ,or he is sure it is, in his best interest….. and It can be easily demonstrate by real examples.