 We may agree, then, that the divine substances in the superlunary realm and the compound substances in the sublunary one have prima facie been vertically integrated into a single explanatory system. As a result, when we look at the form of a sublunary matter-form compound, we will find in it the mark of a superlunary activator, just as we do in the case of the various heavenly bodies, and, as in the line of its efficient causes, we find “the sun and its movement in an inclined circle” (1071a15–16). Still awaiting integration, though, are mathematical objects, such as numbers. But in Books M and N these are shown to be not substantial starting-points and causes but abstractions from perceptible sublunary beings—they are dependent entities, in other words, rather than self-subsistent ones. Similarly, in Physics II.2 we read: