upon the use of the reasoning power,—and the latter of men who maintained that actual experience was the only thing of any serious value. The respective leaders of these two groups or sects were Plato and Aristotle.
In Raphael's celebrated painting, "The School of Athens," these two heroes of philosophy are represented standing side by side—Plato with his right hand elevated and pointing toward heaven, while Aristotle is looking distinctly at the earth. Pictorially, the tendencies of the two schools of philosophy could not have been better represented. Plato's genius had taken its flight heavenward and was contemplating earthly things from this point of vantage; his method being to ignore system and to look at everything with the eyes of purest love. "Delightfully poetic, but thoroughly unprofitable speculation as to what constitutes scientific truth and perfected morality!" (Friedlaender.)
Aristotle, whose father was a physician and a descendant of Aesculapius, was the hero and guiding spirit of those who based their philosophy on experience, on ascertained facts. Like his celebrated pupil, Alexander the Great, who brought whole nations under his sway, he too was a conqueror in every field of human knowledge. His ideas ruled supreme over the minds of men for thousands of years and to-day, although many of them are no longer accepted as valid, Aristotle himself is universally held to have been the greatest thinker and investigator who has ever lived upon this earth. (In chapter XIII. I shall have occasion to say something further regarding the Dogmatics and the Empirics.)
Out of the teachings of Plato and Aristotle developed two schools of philosophy that exerted, in course of time, a great influence upon the minds of men and upon the growth of medical science. The schools referred to are the Epicureans and the Stoics. Epicurus (242-270 B. C.), who gave his name to the first of these, taught that the highest good was happiness.
The happiness he taught his followers to seek was not sensual
enjoyment, but peace of mind as the result of the cultivation of
