 To be clear, however, primitive powers and perceptions do not play the same causal roles, according to Leibniz. Whereas the primitive power of a substance (some commentators maintain that primitive powers and substances are one and the same) is the efficient cause—a post-Humean might say the real cause—of the change of its perceptual states, these states themselves do not function as efficient causes. How perceptual states do function causally is controversial, and we will address this issue later. Whatever the final details of Leibniz’s account happen to be regarding primitive power and perception, one thing is clear: Leibniz’s account runs seriously counter to David Hume’s regarding causation. In 1748, Hume stated that his definition of cause entails that “all causes are of the same kind” (An Enquiry Concerning Human Understanding, 156), whereas Leibniz incorporates efficient, final, and formal causes in his theory of causation. Before discussing these different kinds of causes, however, let us consider a particularly vexed issue in Leibniz’s account of causation: divine causation.