ancient Greek colony in Libya; the name is of unknown origin. Cyrenaic (1640s) typically refers to the philosophy ("practical hedonism") of Aristippus of Cyrene (c. 435-c. 356 B.C.E.); as a noun, "a Cyrenaic philosopher," from 1580s.
According to Aristippus, pleasure is the only rational aim, and the relative values of different pleasures are to be determined by their relative intensities and durations. He maintained also that cognition is limited to sensation. [Century Dictionary]