 The philosopher of Nature enquires about Nature and about the four causes, and we have known the material, formal and efficient causes, but does Nature act for a purpose? Aristotle starts Phys. II.8 saying that he is going to prove that Nature belongs to the final causes (198b10–15) and Averroes observes that this tenet is a basic principle in Physics and Metaphysics (LC 75L TC75). If the philosopher of Nature would deny the existence of purposiveness in it, the other causes would be annulled. Matter exists on the account of form, we have read. Form exists because an agent impresses it on matter, and the agent acts because it wants to achieve an end. And 