Heraclitus

Heraclitus, who flourished around 500 BC, was a pre-Socratic Greek philosopher from the city of Ephesus, then part of the Persian Empire, who exerted wide influence on Western philosophy, both ancient and modern, through the works of authors including Plato, Aristotle, the Stoics, Hegel, Nietzsche and Heidegger. Little is known of his life; he wrote a single work of which only fragments survive, and his paradoxical philosophy, appreciation for wordplay and cryptic, oracular epigrams earned him the epithets "the dark" and "the obscure", and the name "the weeping philosopher" in contrast to the atomist Democritus, known as "the laughing philosopher." The central ideas of his philosophy are the unity of opposites and the concept of change: he viewed the world as constantly in flux, always becoming but never being, expressed in sayings such as "everything flows" and "no man ever steps in the same river twice," a view that contrasts with the ancient philosopher Parmenides, who believed in a reality of static being. Heraclitus believed fire was the arche, the fundamental element of the world, following the Milesians before him who proposed water, the boundless and air, and he also thought the logos, meaning word, discourse or reason, gave structure to the world or existed as a kind of divine law.