As with Empedocles and the Atomists, a moving force is required to explain the world-process of unmixing. What, in the philosophy of Anaxagoras, is this force? Now up to the present point the philosophy of Anaxagoras does not rise above the previous philosophies of Empedocles and the Atomists. On the contrary, in clearness {97} and logical consistency, it falls considerably below the teaching of the latter. But it is just here, on the question of the moving force, that Anaxagoras becomes for the first time wholly original, and introduces a principle peculiar to himself, a principle, moreover, which is entirely new in philosophy. Empedocles had taken as his moving forces, Love and Hate, mythical and fanciful on the one hand, and yet purely physical on the other. The forces of the Atomists were also completely material. But Anaxagoras conceives the moving force as wholly non-physical and incorporeal. It is called Nous, that is, mind or intelligence. It is intelligence which produces the movement in things which brings about the formation of the world. What was it, now, which led Anaxagoras to the doctrine of a world-governing intelligence? It seems that he was struck with the apparent design, order, beauty and harmony of the universe. These things, he thought, could not be accounted for by blind forces. The world is apparently a rationally governed world. It moves towards definite ends. Nature shows plentiful examples of the adaptation of means to ends. There appears to be plan and purpose in the world. The Atomists had assumed nothing but matter and physical force. How can design, order, harmony and beauty be brought about by blind forces acting upon chaotic matter? Blind forces acting upon a chaos would produce motion and change. But the change would be meaningless and purposeless. They could not produce a rationally ordered cosmos. One chaos would succeed another chaos ad infinitum. That alone which can produce law and order is intelligence. There must therefore be a world-controlling Nous. {98}