Pyrrho

Pyrrho of Elis lived around 360 to 270 BC and became the first Greek philosopher to build a system around radical skepticism. He argued that nothing could be known with certainty, so the wise course was to withhold judgment on all matters — a stance called epoché. His refusal to commit to any belief, even sensory evidence, supposedly left him so indifferent to the world that followers had to guide him past hazards. The school of thought he founded, Pyrrhonism, would shape philosophical debate for centuries, turning skepticism into a discipline rather than a posture.