Aristotle

Ar·is·tot·le (r-sttl) 384-322 bc.

Greek philosopher. A pupil of Plato, the tutor of Alexander the Great, and the author of works on logic, metaphysics, ethics, natural sciences, politics, and poetics, he profoundly influenced Western intellectual and scientific thought. In his works on science he emphasized the direct observation of nature and the philosophy that theory follows empirical observation.