hedonism (n.)

1828 in reference to the philosophy; 1844 as "self-indulgence," from Greek hēdone "pleasure" (see hedonist) + -ism.

The doctrine of Aristippus and the Cyrenaic school of Greek philosophers, that the pleasure of the moment is the only possible end, that one kind of pleasure is not to be preferred to another, and that a man should in the interest of pleasure govern his pleasures and not be governed by them; hence, that ethical doctrine which regards pleasure or happiness as the highest good. ... Egoistic hedonism considers only the pleasure of the individual; altruistic hedonism takes into account that of others. [Century Dictionary]