A Stoic philosopher and polymath, and a major influence on Cicero (who attended his school in Rhodes), Strabo, Seneca, and Pompey. What is known of Posidonius’ philosophical views contains little that is specific to him, but he had a universalistic and imperialistic conception of history, the shaping of which combines political and religious duty. He was himself active in politics, and intellectually equally important as a naturalist, mathematician, cosmologist, biologist and historian. He regarded the special sciences as tools of true philosophy, which would synthesize and axiomatize their results. He also discovered a lunar theory of the tides that was not superseded until Newton, and explored the sphericity of the earth, even describing lines of latitude.