Heraclitus

Writing in the 5th century BCE, Heraclitus believed that everything is constantly changing or, as he put it, in flux. He expressed this thought in a famous epigram: "No man ever steps into the same river twice." Heraclitus is often considered an enigmatic thinker and much of his work is complex and puzzling. He was critical of the poets Homer and Hesiod, whom he considered to be ignorant, and accused the mathematician Pythagoras (who may have been his contemporary) of making things up. Heraclitus despaired of men's folly and in his work constantly strove to encourage people to consider matters from alternative perspectives. Donkeys prefer rubbish to gold, he observed, pointing out that the same thing can have different meanings to different people. Unlike most of his contemporaries he was not associated with a particular school or disciplinary approach, although he did have his followers. At times a rationalist, at others a mystic, Heraclitus is an intriguing figure who influenced major later philosophers and movements such as Plato and the Stoics.