Psychological egoism is the view that humans are always motivated by self-interest and selfishness, even in what seem to be acts of altruism.
It claims that, when people choose to help others, they do so ultimately because of the personal benefits that they themselves expect to obtain, directly or indirectly, from doing so.
Accordingly, all actions are tools for increasing pleasure or decreasing pain, even those defined as altruistic and those that do not cause an immediate change in satisfaction levels.
Humanity performs altruistic, honorable, and virtuous acts not for the sake of another or because of a moral code but rather to increase the well-being of the self.
In modern philosophy, Jeremy Bentham asserted, like Epicurus, that human behavior is governed by a need to increase pleasure and decrease pain.
[4] Bentham explicitly described what types and qualities of pain and pleasure exist, and how human motives are singularly explained using psychological hedonism.
From an evolutionary perspective, Herbert Spencer, a psychological egoist, argued that all animals primarily seek to survive and protect their lineage.
[6] The pleasure principle rules the behavior of the Id which is an unconscious force driving humans to release tension from unfulfilled desires.
Operant conditioning works through reinforcement and punishment which adds or removes pleasure and pain to manipulate behavior.
[9] Often, behaviorist experiments using humans and animals are built around the assumption that subjects will pursue pleasure and avoid pain.
Proponents cite evidence from introspection: reflection on one's own actions may reveal their motives and intended results to be based on self-interest.
[13] Other critics argue that it is false either because it is an over-simplified interpretation of behavior[14][15][16] or that there exists empirical evidence of altruistic behaviour.
For example, German philosopher Friedrich Nietzsche was a psychological egoist for some of his career, though he is said to have repudiated that later in his campaign against morality.
In the ninth century, Mohammed Ibn Al-Jahm Al-Barmaki (محمد بن الجـَهْم البَرمَكي) has been quoted saying: "No one deserves thanks from another about something he has done for him or goodness he has done, he is either willing to get a reward from God, therefore he wanted to serve himself, or he wanted to get a reward from people, therefore, he has done that to get profit for himself, or to be mentioned and praised by people, therefore, to it is also for himself, or due to his mercy and tenderheartedness, so he has simply done that goodness to pacify these feelings and treat himself.
Other, less restricted forms of psychological egoism may allow the ultimate goal of a person to include such things as avoiding punishments from oneself or others (such as guilt or shame) and attaining rewards (such as pride, self-worth, power or reciprocal beneficial action).
He expounds it in the following cross-examination: In their 1998 book, Unto Others, Sober and Wilson detailed an evolutionary argument based on the likelihood for egoism to evolve under the pressures of natural selection.
The hedonistic mechanism is based on a parent's ultimate desire for pleasure or the avoidance of pain and a belief that caring for its offspring will be instrumental to that.
Sober and Wilson argue that when evaluating the likelihood of a given trait to evolve, three factors must be considered: availability, reliability and energetic efficiency.
If I voluntarily gave up my life to save the lives of several strangers, my act would not be selfish, though I would be doing what in the wide sense I wanted to do.