Aristotle, Scientist and Philosopher

After studying with Plato, Aristotle (384–322 B.C.E.) founded his own school, the Lyceum, in Athens. He taught his own life-guiding philosophy, emphasizing practical reasoning. Like Plato, he thought Athenian democracy was a bad system because it did not restrict decision making to the most educated and moderate citizens. His vast writings made him one of the world’s most influential thinkers.

Aristotle’s achievements included scientific investigation of the natural world, development of systems of logical argument, and practical ethics based on experience. He believed that the search for knowledge brought the good life and genuine happiness. His teachings covered biology, botany, zoology, medicine, anatomy, psychology, meteorology, physics, chemistry, mathematics, music, metaphysics, rhetoric, literary criticism, political science, and ethics. By creating a system of logic for precise argumentation, Aristotle also established grounds for determining whether an argument was logically valid. Aristotle’s thought process stressed rationality and common sense, not metaphysics. He rejected Plato’s theory of Forms and insisted that understanding depended on observation. He coupled detailed investigation with careful reasoning in biology, botany, and zoology. He collected information on more than five hundred different kinds of animals, including insects. His recognition that whales and dolphins are mammals was not rediscovered for another two thousand years.

Some of Aristotle’s observations justified inequalities that were characteristic of his time. He argued that some people were slaves by nature because their souls lacked the rationality to be fully human. Mistaken biological information led Aristotle to evaluate females as incomplete males, judging them as inferior. At the same time, he believed that human communities could be successful and happy only if women and men both contributed. (See “Document 4.1: Aristotle on the Nature of the Greek Polis.”)

In ethics, Aristotle emphasized the need to develop practical habits of just behavior in order to achieve happiness. Ethics, he taught, cannot work if they consist only of abstract reasons for just behavior. People should achieve self-control by training their minds to overcome instincts and passions. Self-control meant finding “the mean,” or balance, between denying and indulging physical pleasures.