Epicurus, who was born on the Greek island of Samos, traveled to Athens when he was about 18 years old, and received military training. He then taught at Mytilene and Lampsacus before returning to Athens (305 bc) where he founded a school of philosophy and attracted a substantial following.

Epicurus revived Democritean atomism and was little influenced by his predecessors, Plato and Aristotle. His work is known through substantial fragments in the writings of Diogenes Laërtius and especially through the long poem, De rerum natura (On the Nature of Things), by his Roman disciple Lucretius. The Epicurean philosophy aimed at the attainment of a happy, though simple, life and used the atomic theory to sanction the banishment of the old fears and superstitions. Epicurus also made important additions to the atomic theory, asserting the primacy of sense-perception where Democritus had distrusted the senses, and he introduced the concept of random atomic ‘swerve’ to preserve free will in an otherwise deterministic system.