obedient to law; while the unlimited or infinite was that which no law controlled. Out of the union of these two principles, the limiting and the unlimited, the universe arose according to the Pythagoreans. The limiting principle does not limit that which is already limited; such a statement would be absurd. It limits that which in its own nature is unlimited; and out of this combination the beauty and harmony of the universe are formed.
50. Now, this doctrine of the limit and the unlimited (πέρας and τὸ ἄπειρον), which the Pythagoreans applied to all things, this doctrine applied to morals gives rise to the Aristotelic doctrine of the μεσότης, or of virtue as a mean between two extremes. Many passions are in themselves of the nature of the infinite, the unlimited, the excessive; consequently, in themselves they are bad; they are vices. But when checked and controlled by the limit, they become good, they acquire the character of virtues. In fact, all the passions in excess are mere madnesses, and it is their nature to be in excess. But when reduced to finitude, to limit, they become the springs which move the world, the sources out of which all human happiness and all human greatness proceed. Reason or thought is the power which fixes a limit to passion. When this limit is fixed the passion shows as a μεσότης, or mean between two -extremes. Such is the metaphysical, and also historical, explanation of Aristotle's doctrine of the μεσότης. He bor-
