Posterior analytics

Aristotle (384–322 BC), the son of a doctor from Stagira in northern Greece, studied at Plato's Academy for twenty years, tutored the young Alexander the Great and then founded his own school in Athens, the Lyceum, where he is said to have taught while walking.

He wrote on almost everything: logic, physics, biology, ethics, politics, rhetoric and poetry, and his works became the foundation of learning for two thousand years. In the Arabic tradition he was called the First Teacher, and the great commentaries of Ibn Rushd carried his thought back to medieval Europe.