Aristotle

Aristotle

Aristotle (384 B.C.E.—322 B.C.E.)

Aristotle is a towering figure in ancient Greek philosophy, who made important contributions to logic, criticism, rhetoric, physics, biology, psychology, mathematics, metaphysics, ethics, and politics. He was a student of Plato for twenty years but is famous for rejecting Plato’s theory of forms. He was more empirically minded than both Plato and Plato’s teacher, Socrates.

A prolific writer, lecturer, and polymath, Aristotle radically transformed most of the topics he investigated. In his lifetime, he wrote dialogues and as many as 200 treatises, of which only 31 survive. These works are in the form of lecture notes and draft manuscripts never intended for general readership. Nevertheless, they are the earliest complete philosophical treatises we still possess.

As the father of western logic, Aristotle was the first to develop a formal system for reasoning. He observed that the deductive validity of any argument can be determined by its structure rather than its content, for example, in the syllogism: All men are mortal; Socrates is a man; therefore, Socrates is mortal. Even if the content of the argument were changed from being about Socrates to being about someone else, because of its structure, as long as the premises are true, then the conclusion must also be true. Aristotelian logic dominated until the rise of modern propositional logic and predicate logic 2000 years later.

Aristotle’s intellectual range was vast, covering most of the sciences and many of the arts,including biology, botany, chemistry, ethics, history, logic, metaphysics, rhetoric, philosophy of mind, philosophy of science, physics, poetics, political theory, psychology, and zoology. He was the founder of formal logic, devising for it a finished system that for centuries was regarded as the sum of the discipline; and he pioneered the study of zoology, both observational and theoretical, in which some of his work remained unsurpassed until the 19th century. But he is, of course, most outstanding as a philosopher. His writings in ethics and political theory as well as in metaphysics and the philosophy of science continue to be studied, and his work remains a powerful current in contemporary philosophical debate.