 Philosophers have long wondered about the nature of causality. Are there true causes at work in the world, and, if so, what makes them the causes they are? How do causes bring things about, and what kind of connection does a cause have to its effect? These questions took on another level of complexity when various religious and theological considerations were brought to bear on these issues. For instance, philosophers came to question how divine causal activity is to be understood, particularly, in relation to the natural causality of creatures. It is from this context, in which questions about the nature of causation intermixed with questions about the relation between divine and natural causality, that occasionalism emerged. Occasionalism attempts to address these questions by presenting as its core intuition the claim that, regardless of our common sense inclinations, God is the one and only true cause. In the words of the most famous occasionalist of the Western philosophical tradition, Nicolas Malebranche, “there is only one true cause because there is only one true God; … the nature or power of each thing is nothing but the will of God; … all natural causes are not true causes but only occasional causes” (OCM II, 312 / Search 448) A full-blown occasionalist, like Malebranche, then, might be described as one who subscribes to the following two tenets: (1) the positive thesis that God is the only genuine cause; (2) the negative thesis that no creaturely cause is a genuine cause but at most an occasional cause. Not all philosophers who have been identified as occasionalists, however, were full-blown occasionalists in this sense, since some argued that only a limited subset of creatures lack causal powers, and thus affirmed the causal efficacy of other creatures. For these occasionalists, the two theses just stated above would be too strong, and they would subscribe instead to a weaker position along the following lines: while God is the unique genuine cause in some restricted domain, other genuine creaturely causes are operative in the world, and not all creaturely causes are merely occasional causes.