Pyrrho of Elis

An ancient Greek philosopher who left no writings of his own; his teaching survives chiefly through his student Timon of Phlius and its later systematic form in Sextus Empiricus. He accompanied Alexander the Great's campaign into India, reportedly encountering ascetic sages there, and held that since things are equally indifferent, unmeasurable and inarbitrable, the wise response is to suspend judgment, which brings the tranquility that dogmatic certainty cannot.