the later manifestations of this philosophy Sextus Empiricus, who lived in the first half of the third century A.D., must be studied.
2. Aristotle lays down the general principle of the Pythagoreans in the following terms: "Number," he says, "is, according to them, the essence of all things; and the organisation of the universe, in its various determinations, is a harmonious system of numbers and their relations.” "The boldness of such an assertion," says Hegel, "impresses us as very remarkable; it is an assertion which strikes down at one blow all that our ordinary representations declare to be essential and true. It displaces sensible existence, and makes thought and not sense to be the criterion of the essence of things. It thus erects into substance and true being something of a totally different order from that form of existence which the senses place before us." (Werke, xiii. 237-38.)
3. What Pythagoras and his followers meant precisely by number it is not easy to say. One point seems to be certain, that number, in the Pythagorean sense, denoted law, order, form, harmony. It is said that Pythagoras was the first who called the world κόσμος, or order, thereby indicating that order was the essence of the universe—that law or number, or proportion or symmetry, was the universal principle in all things.
4. If we compare this position with that occu-
