Aristotle (384-322 B.C.), a student of Plato and tutor of Alexander the Great, invented a system of logic which remained essentially unchanged in Western European philosophy for more than two millennia following his death. Although his predecessors, Socrates and Plato, had placed great emphasis on correct reasoning, Aristotle was the first philosopher to set forth a carefully worked out system, which, he believed, if followed, could eliminate false reasoning. Some have suggested that Aristotle created the "science" of logic, but, to Aristotle, logic was not simply one of the sciences; rather it was the art and method of correct reasoning, a prerequisite to the study of any science. Followers of Aristotle gave the collection of his writings on logic the name Organon, which means "tool." Logic, for Aristotle, was the principal "tool" for reasoning correctly.

At the heart of Aristotle's logic is the syllogism. Perhaps...