Philosopher. He lived in Athens, but was born in Cyrene in North Africa. Hence his philosophy was referred to as Cyrenaicism and his followers as Cyreniacs. Unlike his master Socrates, Aristippus unashamedly charged his pupils whatever the traffic would bear and by his own profession lived as extravagantly as he could.

Although no work of his survives, Cyrenaicism taught an unalloyed and unrepentant hedonism, with immediate pleasure (very much including physical pleasure) to be pursued, pain avoided, and other objects and ends of little account. But one should approach the pursuit of pleasure with a rational mind and a degree of self-control or pleasure will too easily turn to pain. As Aristippus said of an expensive female companion, "I have Lais, not she me."

It will be apparent that Aristippus's advice to give free rein to desires, to pursue pleasure without remorse, but not to fret over much when desires are thwarted, is actually quite difficult to follow, which ultimately limited its appeal.

Cyrenaicism was sometimes confused with Epicureanism, but in the latter pleasure is defined very differently as a calm, undisturbed mind supported by good physical health, not by physical enjoyment or luxuries.