 As we just saw, Spinoza derives his prohibition of mental explanations of physical actions from what he takes to be true of the relation between the mental and the physical in the case of God. This is an instance of a more general methodological and epistemological principle Spinoza holds dear, that of the explanatory priority of claims about substance (God) to claims about modes (creatures) (E1p1, E1p15). To return to our toy analogy, we can only understand what it is to be a wrinkle in a rug if we first understand what it is to be a rug. For Spinoza, philosophizing in proper order always requires us to start with God (E2p10s).