Epicureanism is a system of philosophy based upon the teachings of Epicurus (c. 341–c. 270 BC), founded around 307 BC. Epicurus was an atomic materialist, following in the steps of Democritus. His materialism led him to a general attack on superstition and divine intervention. Following Aristippus—about whom very little is known—Epicurus believed that the greatest good was to seek modest pleasures in order to attain a state of tranquility and freedom from fear (ataraxia) as well as absence of bodily pain (aponia) through knowledge of the workings of the world and the limits of our desires. The combination of these two states is supposed to constitute happiness in its highest form. Although Epicureanism is a form of hedonism, insofar as it declares pleasure as the sole intrinsic good, its conception of absence of pain as the greatest pleasure and its advocacy of a simple life make it different from "hedonism" as it is commonly understood.
In the Epicurean view, the highest pleasure (tranquility and freedom from fear) was obtained by knowledge, friendship, and living a virtuous and temperate life. He lauded the enjoyment of simple pleasures, by which he meant abstaining from bodily desires, such as sex and appetites, verging on asceticism. He argued that when eating, one should not eat too richly, for it could lead to dissatisfaction later, such as the grim realization that one could not afford such delicacies in the future. Likewise, sex could lead to increased lust and dissatisfaction with the sexual partner. Epicurus did not articulate a broad system of social ethics that has survived.