Starting from this standpoint, Maimonides lays down the principle that virtue is “the mean which is equidistant from both extremes.”[111] This principle is taken, of course, from Aristotle’s doctrine of virtue. But Aristotle did not set up a higher moral criterion by reference to which the mean point could be determined in every case. For him all virtue was really but a code of good manners to which the polite Greek should conform, being enabled by his own good taste to fasten instinctively on the point equidistant from the ugliness of the two extremes. Not so Maimonides, the Jew. He made this principle the basis of morality in the true sense, because he coupled with it a formulation of the supreme moral end. This moral end, for which the virtues are a preparation,[112] compels us and enables us to distinguish between the extremes and the mean. For the extremes, being apt to impair physical health or mental peace, prevent a man from fulfilling his intellectual function; the mean is that which helps him on his road.[113] But with all this we have not yet a complete answer to our question about the purpose of the existence of the human race as a whole. We know that the human race really consists of two different species: “potential man” and “actual man.” The second species, indeed, does not come into existence from the start as an independent species, but is produced by development out of the first. But this development is a very long one, and depends on many conditions which are difficult of fulfilment, so that only a few men—sometimes only “one in a generation”—are privileged to complete it, while the great majority of mankind remains always at the stage of “potential man.” Thus the question remains: What is the purpose of the existence of the great mass of men “who cannot picture the Idea in their souls”? For when we say that all material things exist for the sake of the existence of man, we do not mean that all other things are but a “necessary evil,” an evil incidental to the production of the desired end—in other words, merely Nature’s unsuccessful experiments in her struggle towards “the production of the most perfect being that can be produced,” like the many imperfect specimens of his art that the inexpert artificer turns out before he succeeds in creating one that is perfect. We cannot so regard them in the face of the evidence that we have of the wonderful wisdom of creative nature, which proves that the Artificer can do his work in the way best fitted to achieve his object. We must therefore assume that “things do not exist for nothing”; that Nature, in her progress towards the production of the most perfect being, has formed all other things for the benefit of that most perfect being, whether for food or “for his advantage otherwise than by way of food,” in such a way that the sum-total of things in the inferior world is not merely a ladder by which to ascend to the