Epicurus was an ancient Greek philosopher and sage who founded Epicureanism, a highly influential school of philosophy. He was born on the Greek island of Samos to Athenian parents. Influenced by Democritus, Aristippus, Pyrrho, and possibly the Cynics, he turned against the Platonism of his day and established his own school, known as "the Garden", in Athens. Epicurus and his followers were known for eating simple meals and discussing a wide range of philosophical subjects. He openly allowed women and slaves to join the school as a matter of policy. Of the over 300 works said to have been written by Epicurus about various subjects, the vast majority have been destroyed. Only three letters written by him—the letters to Menoeceus, Pythocles, and Herodotus—and two collections of quotes—the Principal Doctrines and the Vatican Sayings—have survived intact, along with a few fragments of his other writings. As a result of his work's destruction, most knowledge about his philosophy is due to later authors, particularly the biographer Diogenes Laërtius, the Epicurean Roman poet Lucretius and the Epicurean philosopher Philodemus, as well as the hostile but largely accurate accounts by the Pyrrhonist philosopher Sextus Empiricus, and the Academic Skeptic and statesman Cicero.

Ancient Greek philosophy arose in the 6th century BC. Philosophy was used to make sense of the world using reason. It dealt with a wide variety of subjects, including astronomy, epistemology, mathematics, political philosophy, ethics, metaphysics, ontology, logic, biology, rhetoric and aesthetics. Greek philosophy continued throughout the Hellenistic period and later evolved into Roman philosophy.