ally popular among the Romans. It was ethics, a philosophy of practice rather than of knowledge. The Stoic looked out upon the world from the inner fortress of the human will. That guarded or rather constituted his well-being. He cared for such knowledge, call it instruction rather, as would make good the principle that human well-being lay in the rightly self-directing will. He did not seriously care for metaphysics, or for knowledge of the natural world, save as one or the other subserved the ends of his philosophy as a guide of life. Thus the Stoic physics, so important a part in the Stoic system, was inspired by utilitarian motives and deflected from unprejudiced observation by teleological considerations and reflections on the dispensations of Providence. Of course, some of the Stoics show a further range of intellectual interest; Seneca, for example, who was a fine moralist and wrote beautiful essays upon the conduct of life. He, like a number of other people, composed a book of Quaestiones naturales, which was chiefly devoted to the weather, a subject always very close to man. But he was not a serious meteorologist. For him the interest of the fact lay rather in its use or in its moral bearing. After Seneca the Stoic interest in fact narrows still further, as with Epictetus and Marcus Aurelius.
Like things might be said of the school of Epicurus, a child of different colour, yet birthmate of the Stoa. For in that philosophy as in Stoicism, all knowledge beyond ethics had a subordinate rôle. As a Stoic or Epicurean, a man was not likely to contribute to the advance of any branch of science. Yet habits of eclectic thought and common curiosity, or call it love of knowledge, made many nominal members of these schools eager students and compilers from the works of others.
We have yet to speak of the system most representative of latter-day paganism, and of enormous import for the first thousand years of Christian thought. Neo-Platonism was the last great creation of Greek philosophy. More specifically, it was the noblest product of that latter-day paganism which was yearning somewhat distractedly, impelled by cravings which paganism could neither quench nor satisfy.
