Davis Kuykendall

Leibniz argued that in natural world, only intra-substantial or immanent causation is possible— the causation that takes place within an individual, when an individual brings about a change in itself. In this dissertation, I address issues arising from Leibniz’s arguments against the rival view that posits a world of causally interacting substances and issues pertaining to Leibniz’s own positive metaphysics of immanent causation and change. Chapter 1 is devoted to stage setting for the remainder of the dissertation. I first offer a historically informed overview of efficient causation and change before introducing Leibniz’s novel views, including his criticisms of competing accounts and his own positive account. After presenting a detailed roadmap of my project, I articulate the idealistic interpretation of Leibniz assumed in this dissertation, where the only genuine substances are simple monads. Finally, I articulate the methodological approaches I employ. In Chapters 2 and 3, I reconstruct and assess Leibniz’s most frequent argument against transeunt causation (the causation that occurs when a substance produces a property in a numerically distinct substance), what I call the “Transference Argument.” Leibniz argued that a created substance’s causing an accident in a numerically distinct substance is possible only if the agent transfers the accident from itself to the patient, where upon transference the agent no longer possesses the accident it transferred. Call the transeunt causal requirement that the agent transfer the accident produced from itself to the patient the “Transference Condition.” Chapter 2 is devoted to two problems with Leibniz’s transference condition. First, Leibniz stated the transference condition throughout his career, but offered little argument for it. Second, God is a transeunt cause in Leibniz’s metaphysics yet God’s causation does not consist in transference. Thus, Leibniz needs a principled way to require transference for creaturely causation while denying that divine transeunt causation consists in transference. Finally, I close off chapter 2 by drawing attention to an important weakness with the transference condition that has not yet been recognized by Leibniz scholars. In Chapter 3, I argue that there is nothing in Leibniz’s ontology that could be transferred from the cause to the recipient of the effect. I first argue that Leibniz’s ontology consists of simple non-corporeal substances and their modifications. Second, I present and articulate a number of important theses Leibniz affirmed about substances and their modifications, which entail that neither could be transferred. I also show that most of these theses were not unique to Leibniz, but were in fact widely endorsed by his predecessors who defended the possibility of creaturely transeunt causation. In chapter 4, I continue the study of the nature of Leibnizian accidents, shifting the focus from their role in Leibniz’s critique of creaturely transeunt causation to their positive role in change and as causal relata, where such accidents are the effects of immanent causation. I shall argue that Leibniz’s thesis that accidents are modifications or limitations allowed him to posit mereologically simple substance that have a multitude of accidents at a time and change accidents over time. In Chapter 5, I address an issue that has divided Leibniz scholars concerning the precise relata in Leibnizian immanent efficient causation. In many passages, Leibniz writes as if it is the substance or individual itself that efficiently causes its later properties or accidents. Call this the “Efficacious-substance” account. The efficacious-substance account is difficult to reconcile with Leibniz’s requirements that change be intelligible and deterministic. In plenty of other passages, he writes as if it is the substances earlier properties or accidents that cause its later accidents. Call this the “Efficacious-accident” account. The efficacious-accident account explains how change is intelligible and deterministic but it faces a “plurality of agents” objection. If a substance’s accidents are the efficient causes of later accidents, then prima facie there is a plurality of efficient causal agents in a substance. This view is incompatible with Leibniz’s requirement that substances be simple, unified entities. Drawing upon a Scholastic distinction made between two kinds of efficient causes— principle quod efficient causes and principle quo efficient causes, I shall argue that for Leibniz, substances are principle quod efficient causes and their appetitions are principle quo efficient causes. This interpretation combines the strengths of the Efficacious-substance and Efficacious-accident accounts while overcoming their weaknesses. There is just one causal agent, the substance, but change is both intelligible and deterministic because as what an agent produces is explained by its appetitions.

In this paper, I defend the agent/patient distinction against critics who argue that causal interactions are symmetrical. Specifically, I argue that there is a widespread type of causal interaction between distinct entities, resulting in a type of ontological asymmetry that provides principled grounds for distinguishing agents from patients. The type of interaction where the asymmetry is found is when one of the entities undergoes a change in kind, structure, powers, or intrinsic properties as a result of the interaction while the other does not. Interactions of this type are widespread in molecular biology and chemistry. I focus specifically on (i) the actions of enzymes on substrates and (ii) water molecules breaking the bonds of polarized molecules. Finally, I respond to objections by laying out and to a limited extent defending three commitments of my account: emergent entities and powers, realism about chemical kinds or structures, and the assumption of the agent/patient distinction in functional attributions in biology.

To address what I call the “Uniformity”, “Capriciousness”, and “Reducibility” objections, recent agent-causation theories hold that agent-causation is a type of substance causation. Substance causation consists in substances producing effects by exercising or manifesting their powers. Importantly, these versions of agent-causation assume a realist metaphysics of powers, where powers are properties of substances that can exist unmanifested. However, the realist theories of powers that agent-causal theories have relied upon explicitly hold that powers—rather than their substances—are causes. Substances are merely derivative causes, as the bearers of powers. Critics therefore argue that agent-causation is reducible to causation by the agent’s powers. In this paper, I argue that agent-causation is reducible to causation by the agent’s powers only if powers are self-exemplifying properties. I also offer reasons for why powers—especially agent-causal powers—are non-self-exemplifying properties, in support of the irreducibility of agent-causation.

Leibniz argued that (i) substantial forms only begin to exist via Divine creation; (ii) created substances cannot transeuntly cause accidents in distinct substances; and yet (iii) created substances immanently produce their accidents. Some of Leibniz’s support for (i) came from his endorsement of a widely-made argument against the eduction of substantial forms. However, in defense of eduction, Suárez argued that if creatures cannot produce substantial forms, they also cannot produce accidents, threatening the consistency of (i) and (iii). In this paper, I argue that Leibniz successfully defends the consistency of (i) and (iii) against Suárez’s argument, but at the expense of the consistency of (ii) and (iii).

I argue that the debate between proponents of substance causation and proponents of causation by powers, as to whether substances or their powers are causes, hinges on whether or not powers are self-exemplifying or non-self-exemplifying properties. Substance causation is committed to powers being non-self-exemplifying properties while causation by powers is committed to powers being self-exemplifying properties. I then argue that powers are non-self-exemplifying properties, in support of substance causation.