The theory in Ethics which places man's summum bonum in self. The correlative of altruism, or the theory which places our own greatest happiness in making others happy. Egoism is selfishness pure, altruism is selfish benevolence. “Egoist,” a disciple of egoism.
“To say that each individual shall reap the benefits brought to him by his own powers ... is to enunciate egoism as an ultimate principle of conduct.” —Spencer: Data of Ethics, p. 189.