Aristotle

A man of immense learning and curiosity, Aristotle (Aristoteles) can be seen as the most influential Western thinker prior to the 19th century C.E. Aristotle spent 20 years as the student of the great Athenian philosopher Plato, but he eventually rejected his teacher’s otherworldly doctrines to concentrate on better understanding the material world around him. Aristotle was as much interested in defining problems as in finding answers, and he created categories of systematic research that are still used today, including “logic,” “biology,” and “physics.”

David Sacks, Encyclopedia of the Ancient Greek World, rev. ed., rev. Lisa R. Brody (New York: Facts On File, 2005), 47.