"Generally, it is true, we are inclined to think of the transition from polytheism to monotheism as being at the same time a transition from crude anthropomorphism to a purer notion of God. A middle stage, a de-anthropomorphisized polytheism, appears as a logical construction rather than a living reality. But it seems that Aristotle (and, perhaps, Plato, too) represents just this intermediary stage. It was the anthropomorphism or anthropopathism of the popular religion by which they were repelled, not its plurality of gods".
"Aristotle's Unmoved Movers" in Traditio (1946), p.28