The rest of the story of Greek philosophy is soon told, for it is the story of decay. The post-Aristotelian is the least instructive of the three periods of Greek thought, and I shall delineate only its main outlines. The general characteristics of the decay of thought which set in after Aristotle are intimately connected with the political, social, and moral events of the time. Although the huge empire of Alexander had broken up at the conqueror's death, this fact had in no way helped the Greek States to throw off the yoke of their oppressors. With the single exception of Sparta, which stubbornly held out, they had become, for all intents and purposes, subject to the dominion of Macedonia. And the death of Alexander did not alter this fact. It was not merely that rude might had overwhelmed a beautiful and delicate civilization. That civilization itself was decaying. The Greeks had ceased to be a great and free people. Their vitality was ebbing. Had it not been one conqueror it would have been another. They were growing old. They had to give way before younger and sturdier races. It was not so many years now before Greece, passing from one alien yoke to another, was to become no more than a Roman province. {340} Philosophy is not something that subsists independently of the growth and decay of the spirit of man. It goes hand in hand with political, social, religious, and artistic development. Political organization, art, religion, science, and philosophy, are but different forms in which the life of a people expresses itself. The innermost substance of the national life is found in the national philosophy, and the history of philosophy is the kernel of the history of nations. It was but natural, then, that from the time of Alexander onwards Greek philosophy should exhibit symptoms of decay.