 Occasionalism and pre-established harmony emerged as alternatives to the model of interactionism, in rejecting that there is genuine causal interaction. In fact, their denial of real causal interaction among distinct finite substances is not limited to mind-body interaction but applies across all board, be it body-body or mind-body causation. In other words, both views can be said to deny all inter-substantial causation, where by “substance” we refer to finite substances or  creatures.[12]  However, occasionalism and pre-established parted ways when it came to the question of intra-substantial causation—that is, whether or not there is causal activity going on within the substances such that finite substances are active in causing their own states. Leibniz, the principal proponent of pre-established harmony, held firm to the view that, while finite substances do not have the causal power to bring about changes in other substances, they are causally active internally, that is, in causing their own states. Each creature causally contributes to the occurrence of its own states, and the apparent interaction between distinct substances is due to how the states of distinct substances harmonize with each other. Following our characterization of occasionalism at the outset, even if the relevant domain of concern is restricted to the states of a single, individual substance, an occasionalism would have to hold that the creature itself is not playing a genuine causal role in the occurrence of those states. Leibniz, as a proponent of genuine intra-substantial causal forces, would reject this claim. Malebranche, in contrast, denied all causal powers to creatures, including the intra-substantial powers endorsed by Leibniz. For Malebranche, even the internal states of a creature are mere occasions for God to bring about the relevant subsequent states.