There is a strong emphasis on teleology in nature, and on the inadequacy of causal accounts that omit this. The major context for this is UP, a text explicitly inspired by Aristotle. In this 17-volume magnum opus, Galen goes through the parts of the body one by one, in each case giving an account which justifies the proposition of the purposive nature of its construction. Taking Aristotle’s approach (especially that of Parts of Animals), and the motto “Nature does nothing in vain”, as starting-points, he is concerned to prove the perfect, providential nature of the construction of parts for the benefit of the animal, especially in the context of humans. Important, from the outset, is to insist upon the correct direction of causation: we have hands, etc., because we are intelligent (the view he attributes to Aristotle), not the other way round (the view he attributes to Anaxagoras) (UP I.3, 69–70).