 The previous section followed the order of discovery, beginning with what is better known to us. Here we start with what is causally prior, and so begin with the First Cause. (On Ibn Rushd’s method of inquiry see Cerami 2015 ch. 7.) Although the existence of some kind of First Cause was undisputed, religious and philosophical authorities disagreed about the nature of creation. The most common view was that the world came into existence, from God, after having not existed, but Ibn Rushd follows Aristotle in supposing that the world has always existed, eternally. His strategy for explaining how an eternal world can have a First Cause turns on distinguishing between two kinds of causal orderings, essential and accidental.