Aristotle vs. The Stoics

There are essentially two schools of logical thought that arose at around the same time in the classical world. One, called the Peripatetic, was originated by Aristotle from his great work, the Organon, the other, called the Stoic, was developed by the lesser-known Chrysippus from the teachings of the Megarians.

The difference between the two schools was essentially that Aristotle examined logic from the point of view of analyzing precisely why some demonstrations (of the kind practiced by the Pythagoreans, for instance) "worked", logically speaking, and why some were invalid. Chrysippus was more interested in analyzing dialectic arguments of the kind actually used by Greek scholars around that time. Such argument was termed "eristic" by Plato, since it was carried out not as a means to a particular legalistic or moral end, but simply as a diversion from the illogic of everyday life. Plato scorned the "wranglers", and their argumentation has gotten a bad rap ever since.

Historians today believe that the Stoic school of philosophy was at least as important to the development of logic as the Peripatetic, as it gives us a greater insight into the way "logical" people of that time considered questions.