Occasionalism

Historical Background and Core Thesis

Occasionalism is a family of doctrines asserting that God (or a single, ultimate substance) is the only genuine cause, while created or finite things have no real causal efficacy. What are ordinarily called causes in nature—such as fire burning paper or a moving billiard ball striking a stationary one—are, on this view, merely occasions for divine action. The appearance of creaturely causation is explained by God’s constant and orderly intervention.

Historically, occasionalist ideas appear in several traditions. In medieval Islamic theology, especially within the Ashʿarite school (e.g., al-Ghazālī), occasionalism grounded divine omnipotence and the contingency of the world: only God truly causes; natural “causes” are customary sequences established by divine habit. In Latin Christendom, occasionalist tendencies can be found in some scholastic discussions, but the doctrine becomes especially prominent in early modern Europe in response to Cartesian dualism and mechanistic physics.

In the 17th century, philosophers such as Arnold Geulincx and Nicolas Malebranche developed systematic occasionalist metaphysics. They aimed to reconcile new science, the problem of mind–body interaction, and a robust conception of divine sovereignty. The central thesis in this context is that finite substances, whether mental or material, cannot bridge the gap required to produce genuine effects; only God can do so. Events in created things are therefore occasions on which God brings about corresponding events, according to stable laws of nature understood as expressions of divine volition.

Major Forms of Occasionalism

Islamic Occasionalism (Ashʿarite Tradition)

In classical Islamic kalām, especially Ashʿarite theology, occasionalism serves to protect God’s absolute power and freedom. Created things are thought to be momentary, continuously re-created by God. What appear as causal connections—fire burning cotton, medicine healing the sick—are in reality sequences where God creates both the “cause” and the “effect” in close temporal succession.

Here, natural causes have at most a descriptive role: they mark regular sequences but possess no intrinsic power. The regularity of nature is grounded in divine custom (ʿāda), not in the inherent natures of things. Some Christian scholastics later perceived similarities between these views and certain strands of Christian theology, although the intellectual lineages remain debated.

Geulincx: Ethical and Metaphysical Limits of Human Power

Arnold Geulincx (1624–1669), a Flemish Cartesian, adopted occasionalism primarily to address the mind–body problem and to draw ethical conclusions about human dependence on God. His principle “Where you do not know how, you do not act” supports the conclusion that humans cannot be true causes of bodily motions (for example, voluntary arm movements), since they have no understanding of the physical mechanism involved. Hence, on Geulincx’s view, God coordinates mental volitions with bodily changes; the mind’s willing an action is merely the occasion on which God produces the corresponding bodily motion.

This metaphysical stance underwrites an ethics of humility and resignation: recognizing our lack of genuine causal power encourages moral dependence on divine providence. For Geulincx, occasionalism is not only a theory of causation but also a spiritual and ethical orientation.

Malebranche: Vision in God and the Only True Cause

Nicolas Malebranche (1638–1715) offers the most extensive early modern defense of occasionalism. Within his wider system—featuring the doctrine of the “vision in God” (the claim that we perceive things by seeing their intelligible archetypes in God)—Malebranche argues that only God possesses the power necessary for real causation. Created things are, at best, occasional causes: they are circumstances or conditions under which God, by his general volitions, regularly produces certain effects.

Malebranche’s occasionalism functions on several fronts:

• Mind–body interaction: mental states do not physically move bodies; rather, when a person wills to move, God, following general laws, brings about the bodily movement.
• Intra-physical causation: material bodies, as passive and extended, have no power to produce changes; God moves them according to mechanical laws.
• Divine simplicity and wisdom: God acts through simple, general laws rather than ad hoc interventions, maintaining both the regularity of nature and divine freedom.

Malebranche thus integrates occasionalism into a broad metaphysical, epistemological, and theological framework.

Arguments, Objections, and Legacy

Motivations and Arguments

Several motives have historically supported occasionalism:

1. Divine Omnipotence and Conservation
   Occasionalists argue that if God continuously conserves all things in being, and if conservation is indistinguishable from continued creation, then God is already doing all the metaphysical “work” required for events to occur. Attributing genuine causal power to creatures risks either limiting God’s power or duplicating it.

2. Mind–Body Problem
   Under Cartesian dualism, mind and body are distinct substances with incompatible attributes (thinking vs. extension). Occasionalists contend that such radically different substances cannot directly interact; God must mediate their correspondence, turning each apparent interaction into an occasion for divine action.

3. Skepticism about Necessary Connection
   Some occasionalists anticipate later empiricist concerns (e.g., Hume) about our lack of perceived necessary connection between cause and effect. Since we only observe constant conjunctions, they infer that the true necessary connection lies not in creatures but in God’s will.

4. Simplicity of Explanatory Principles
   By rooting all real causation in a single, omnipotent source, occasionalism promises a metaphysically unified and simple explanation of the world, with laws of nature as expressions of divine habits or volitions.

Objections and Criticisms

Critics have raised several influential objections:

1. Denial of Creaturely Agency
   If only God really causes, it appears that human beings lack genuine free agency and moral responsibility. Actions like choosing, promising, or harming others seem reduced to mere occasions for divine acts, raising the worry that God becomes the direct cause of all sins.

2. Occasionalism as “Perpetual Miracle”
   Opponents such as Leibniz argued that occasionalism turns the ordinary course of nature into a continuous miracle, contrary to the idea of a wisely ordered creation where finite things have real powers. For Leibniz, a perfect creator would endow creatures with genuine causal efficacy.

3. Explanatory Vacuity
   Some have claimed that occasionalism does little explanatory work. Saying “God does it” whenever one event follows another may seem to bypass the search for natural mechanisms that modern science successfully uncovers and systematizes.

4. Tension with Stability of Laws
   If divine will is absolutely free and unconstrained, it may be difficult to explain why laws of nature are so stable and predictable without appealing to something like created natures or powers—precisely what occasionalism denies.

Legacy and Contemporary Relevance

While strict occasionalism largely fell out of favor with the rise of Newtonian physics and later scientific naturalism, its themes continue to influence several areas:

• Philosophy of Religion: Occasionalist ideas inform debates about divine action, providence, and miracles, especially in contexts where theologians wish to stress God’s continuous involvement in the world.
• Metaphysics of Causation: Occasionalism serves as a limiting case or contrast class in discussions about powers, laws of nature, and counterfactual dependence. Contemporary philosophers sometimes invoke it when exploring radical dependence or anti-realist views about causation.
• Mind–Body and Mental Causation: Analogies to occasionalism appear in some versions of epiphenomenalism or non-interactionist accounts, where mental events are said not to cause physical events but to correlate with them according to underlying laws.
• Comparative Philosophy: Occasionalism provides a point of comparison between Islamic kalām, Christian theology, and early modern European philosophy, illustrating convergent strategies for safeguarding divine omnipotence and addressing metaphysical puzzles.

Today, occasionalism is primarily studied as a historically significant doctrine that crystallizes central tensions between divine power, natural law, and creaturely agency. It continues to serve as a reference point for assessing how far metaphysical dependence on a single, ultimate source can be taken without undermining the reality of natural and human causation.