The background to Aristotle’s view as developed in the Physics is a critique of the theories of atomists like Leucippus and Democritus, who favored a materialist explanation of the world which eschews final causes altogether, and the view of Anaxagoras that the order of the world requires an explanation in terms of a divine intelligence. Aristotle’s view is the middle ground position that there is such a thing as goal-directedness in nature, but that it is entirely immanent to the natural order: “That which is by nature and natural is never disordered. For nature is everywhere a cause of order.” (Physics 252a11-12, as translated by Monte Ransome Johnson in his book Aristotle on Teleology) For Aristotle, to be “natural” is ipso facto to be ordered in the sense of having an end toward which one is directed. That which requires an outside source to order or direct it toward an end would, for him, by that very fact not be a natural object at all but an artifact. . . .
That is not to say that final causality plays no role at all in Aristotle’s account of God’s relationship to the world. For he also famously holds that the way the Unmoved Mover moves the world is as a final cause, as the perfect end toward which things are naturally directed. And as the quotation from the Eudemian Ethics indicates, wisdom itself directs us toward the Unmoved Mover, the “service and contemplation” of whom is in Aristotle’s view the highest end of human existence (Eudemian Ethics 1249b21). But this is perfectly consistent with his view that final causes themselves are just part of the natural order, not put into things by God. “The Unmoved Mover is the final cause of things” does not entail “The Unmoved Mover orders things toward their final causes.” Rather, the fact that all things have the Unmoved Mover as their ultimate end is, for Aristotle, itself just a basic feature of reality – and something the Unmoved Mover himself, as Aristotle conceives of him, is too lofty to give any thought to.