egoism, in ethics, the doctrine that the ends and motives of human conduct are, or should be, the good of the individual agent. It is opposed to altruism, which holds the criterion of morality to be the welfare of others. The term has been variously used, from the benevolent self-interest of the utilitarians to the belief, articulated by Friedrich Nietzsche, that all altruistic sentiment is cowardice. Egoism is frequently associated with the ethics of the early Greek hedonists. Some modern philosophers attempt to reconcile egoism and altruism by adducing the concept of the growing self who invests his interests in an ever-widening field.

In ethics, the principle that we should each act so as to promote our own interests. The great advantage of such a position is that it avoids any possible conflict between morality and self-interest; if it is rational for us to pursue our own interest, the rationality of morality is equally clear. The prescriptive thesis of ethical egoism can be distinguished from the descriptive thesis of psychological egoism. Psychological egoism is a generalization about human motivation, namely, that everyone always acts so as to promote his or her own interests.

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