(3) Even if the existence of things is explained by the Ideas, their motion is not. Suppose that the Idea of whiteness produces white things, the Idea of beauty beautiful things, and so on, yet, since the Ideas themselves are immutable and motionless, so will be the world which is their copy. Thus the universe would be {263} absolutely static, like Coleridge's "painted ship upon a painted ocean." But the world, on the contrary, is a world of change, motion, life, becoming. Plato makes no attempt to explain the unceasing becoming of things. Even if the Idea of whiteness explains white objects, yet why do these objects arise, develop, decay, and cease to exist? To explain this there must be some principle of motion in the Ideas themselves. But there is not. They are immovable and lifeless. (4) The world consists of a multitude of things, and it is the business of philosophy to explain why they exist. By way of explanation Plato merely assumes the existence of another multitude of things, the Ideas. But the only effect of this is to double the number of things to be explained. How does it help thus to duplicate everything? And Aristotle likens Plato to a man who, being unable to count with a small number, fancies that, if he doubles the number, he will find it easier to count. (5) The Ideas are supposed to be non-sensuous, but they are, in fact, sensuous. Plato thought that a non-sensuous principle must be sought in order to explain the world of sense. But not being able to find any such principle, he merely took the objects of sense over again and called them non-sensuous. But there is, in fact, no difference between the horse and the Idea of the horse, between the man and the Idea of the man, except a useless and meaningless "in-itself" or "in-general" attached to each object of sense to make it appear something different. The Ideas are nothing but hypostatized things of sense, and Aristotle likens them to the anthropomorphic gods of the popular religion. "As {264} these," he says, "are nothing but deified men, so the Ideas are nothing but eternalized things of nature." Things are said to be copies of Ideas, but in fact the Ideas are only copies of things. (6) Next comes the argument of the "third man," so called by Aristotle from the illustration by which he explained it. Ideas are assumed in order to explain what is common to many objects. Wherever there is a common element there must be an Idea. Thus there is a common element in all men, and therefore there is an Idea of man. But there is also an element common to the individual man and to the Idea of man. There must, therefore, be a further Idea, the "third man," to explain this. And between this further Idea and the individual man there must be yet another Idea to explain what they have in common, and so on _ad infinitum_.