Aristotle Ar·is·tot·le (ār'ĭ-stŏt'l), 384-322 b.c.
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.
One of the greatest ancient Greek philosophers, with a large influence on subsequent Western thought. Aristotle was a student of Plato and tutor to Alexander the Great. He disagreed with Plato over the existence of ideal Forms and believed that form and matter are always joined. Aristotle's many books include Rhetoric, the Poetics, the Metaphysics, and the Politics.