Epicureanism is a system of philosophy founded around 307 BC based upon the teachings of the ancient Greek philosopher Epicurus. Epicureanism was originally a challenge to Platonism. Later its main opponent became Stoicism. Although Epicureanism is a form of hedonism insofar as it declares pleasure to be its sole intrinsic goal, the concept that the absence of pain and fear constitutes the greatest pleasure, and its advocacy of a simple life, make it very different from "hedonism" as colloquially understood.