Malebranche, Nicolas (1638–1715)

4. Occasionalism

Just as the doctrine of the vision in God demonstrates the epistemological dependence that we as knowers have upon God, so the causal doctrine of occasionalism demonstrates the ontological dependence that we and all beings have upon an omnipotent God (see Occasionalism). Nothing, it claims, exists or happens in the universe that is not a direct and immediate effect of the divine will. Although occasionalism has its ancestry in certain medieval Islamic, Jewish and Christian theories of causation and divine omnipotence, especially the voluntarist tradition (see Al-Ghazali; Damian, P.), as well as in Descartes’ metaphysics; and while there were others before Malebranche who were, to one degree or another, occasionalists (see Clauberg, J.; Cordemoy, G. de; Geulincx, A.; La Forge, L. de), Malebranche was the first to argue systematically for a thoroughgoing and rigorous version of the doctrine.

Occasionalism is the doctrine that all finite created entities are absolutely devoid of causal efficacy and that God is the only true causal agent. God is directly, immediately and solely responsible for bringing about all phenomena. When a needle pricks the skin, the physical event is merely an occasion for God to cause the appropriate mental state (pain); a volition in the soul to raise an arm or to think of something is only an occasion for God to cause the arm to rise or the idea to be present to the mind; and the impact of one billiard ball upon another is an occasion for God to move the second ball. In all three contexts – mind–body, mind alone and body–body – God’s ubiquitous causal activity proceeds in accordance with certain general laws, and (except in the case of miracles) he acts only when the requisite material or psychic conditions obtain.

Far from being an ad hoc solution to a Cartesian mind–body problem as it has traditionally been portrayed, occasionalism is argued for by Malebranche (and others) from general philosophical considerations of the nature of causal relations, from an analysis of the Cartesian concept of matter and, perhaps most importantly, from theological premises about the essential ontological relationship between an omnipotent God and the created world that he sustains in existence.

Malebranche’s first argument that there are no real causal powers in finite created substances and that God is the sole causal agent, focuses on the motion of bodies. He begins with the causal principle that in order for one thing, A (which can be a substance or a state of being of a substance), to count as the cause of another thing, B, there must be a necessary connection between the existence of A and the existence of B. ‘A true cause as I understand it is one such that the mind perceives a necessary connection [liaison nécessaire] between it and its effects’ (1674–5 vol. 2: 316). But we can find no such connection between any two physical events, nor between any human mental event and a corresponding physical event. For example, it is certainly conceivable that one can will to raise one’s arm but the arm will not rise. ‘When we examine our idea of all finite minds, we do not see any necessary connection between their will and the motion of any body whatsoever. On the contrary, we see that there is none and that there can be none’ (1674–5 vol. 2: 313). When we consider God, however, as an infinitely perfect being, we see that there is such a necessary connection between the divine will and the motion of bodies, since it is logically impossible that an omnipotent God should will to move a body and it does not move; such is the nature of omnipotence. God, therefore, is the only true cause of the motion of bodies.

Malebranche’s second argument is based on the ‘inconceivability’ that any natural cause, any finite mind or material body, should have ‘a force, a power, an efficacy to produce anything’ (1674–5 vol. 3: 204). First, an idea of body – that is, the clear and distinct idea of extension – represents it as having only one property: the entirely passive faculty of ‘receiving various figures and various movements’ (1688: 148). It certainly does not represent body as having any active power. Here Malebranche is drawing out the ramifications of Descartes’ conception of matter: a Cartesian material body, qua pure extension, is essentially passive and inert, and devoid of any motive force. In fact, such a force or power is perceived as incompatible with the notion of extension, since it cannot be reduced to or explained in terms of relations of shape, divisibility and distance. Thus, bodies cannot act, whether on minds or other bodies. Second, whatever minimal knowledge I have of my soul does not involve the perception of any power, whether to move the body or even to produce its own ideas. All I perceive through inner consciousness is an actual volition to move my arm upwards, and all I notice in my body is that my arm subsequently rises. But I do not perceive, either by inner consciousness or by reason, any power on the part of the soul by means of which it might effect this motion. It is in this sense that ‘those who maintain that creatures have force and power in themselves advance what they do not clearly perceive’ (1674–5 vol. 3: 204). Indeed, according to Malebranche, I perceive a general incompatibility between the idea of a created finite being and such a power or productive faculty. Only in my idea of the will of an infinite being do I clearly and distinctly recognize any element of power whatsoever.

The third argument is based on a supposedly intuitive premise which (echoing an argument for occasionalism introduced by Geulincx) sets an epistemic condition on the notion of ‘cause’: in order to count as the cause of an effect, a thing must know how to bring about that effect. Malebranche then appeals to the evident fact that this condition is not satisfied by our minds in order to show that we do not, in fact, cause those motions that we consider voluntary: ‘There is no man who knows what must be done to move one of his fingers by means of animal spirits’ (1674–5 vol. 2: 315). This same condition rules out the mind’s ability to produce its own ideas. It also rules out, a fortiori, the possession of causal efficacy by bodies.

Malebranche’s most general argument against real interaction appeals to God’s role as creator and sustainer of the universe. The argument – which has its roots in both medieval and Cartesian doctrines – purports to show that it is an ‘absolute contradiction’ that anything besides God should move a body. God’s activity is required not only to create the world, but, since creatures are absolutely dependent on God, to sustain it in existence as well. Indeed, for God there is no essential difference between creating and sustaining: ‘If the world subsists, it is because God continues to will that the world exist. On the part of God, the conservation of the creatures is simply their continued creation’ (1688: 316). When God conserves/recreates a body, he must recreate it in some particular place and in some relation of distance to other bodies. If God conserves it in the same relative place from moment to moment, it remains at rest; if God conserves it successively in different places, it is in motion. But this means that God is and can be the only cause of motion: ‘The moving force of a body, then, is simply the efficacy of the volition of God who conserves it successively in different places…. Hence, bodies cannot move one another, and their encounter or impact is only an occasional cause of the distribution of their motions’ (1688: 162). And finite minds are no more causes of motion than bodies are.

Thus, God is the direct and efficacious cause of every event in nature; finite beings are only ‘secondary’ or ‘occasional’ causes. Malebranche’s doctrine can be seen as embedded within a voluntarist tradition that extends from certain medieval thinkers – many of whom attacked the Aristotelian theory of nature in the name of safeguarding God’s omnipotence – up through Descartes (see Voluntarism).

This does not mean that for Malebranche natural philosophy has been reduced to a single theocratic claim. At the level of physics proper, the task of the scientist is still to uncover regularities in nature and formulate the laws that govern the correlations between events. The programme of the mechanical philosophy, to which Malebranche enthusiastically subscribes, remains the same: to discover the hidden mechanisms that underlie observed phenomena and to frame such explanations (referring to secondary causes) solely in terms of matter and motion. What Malebranche’s occasionalism does is to give an account of the metaphysical foundations of Cartesian physics. Motion, the primary explanatory element in the new science, must ultimately be grounded in something higher than the passive inert extension of Cartesian bodies; it needs a causal ground in an active power or force. Because a body consists in extension alone, motive force cannot be an inherent property of bodies. Malebranche accordingly – and his account seems to be a logical extension of the role Descartes gives to God as the ‘universal and primary cause of motion’ (see Descartes, R. §§6, 11) – places the locus of force in the will of God, and bodies behave the way they do because that is how God moves them around, following the laws of nature he has established.

Malebranche did, in fact, use his metaphysics of motion to modify some details of Descartes’ physics, particularly the rules governing bodily impact. This led to an extended debate with Leibniz over the laws of motion. In the Recherche Malebranche insists, contrary to Descartes, that bodies at rest do not have a force to remain at rest (unlike bodies in motion, which have a force to remain in motion). This conclusion follows directly from his occasionalist account of motion: although God does need to will positively to put a body in motion, he does not need to apply any force to keep it at rest; all he needs to do is will that it continue to exist, that is, recreate it in the same relative place. Thus, the tiniest body in motion will contain more force than the largest body at rest. And this means that three of Descartes’ seven rules of impact are wrong. Leibniz, in his general critique of Cartesian physics, praised Malebranche for recognizing Descartes’ errors. He insisted, however, that because Malebranche was still wedded to Descartes’ conservation law (where what is conserved is quantity of motion, rather than the quantity of motive force that Leibniz proposed), Malebranche has failed to see that all except the first of Descartes’ rules, along with the new rules he had substituted for the ones he rejected, were wrong (see Leibniz, G.W. §11). In 1692, Malebranche published his Des lois de la communication des mouvements, in which he concedes that Leibniz is right about the rules themselves, but continues to maintain the old conservation law. It was not until a letter to Leibniz in 1699 and the 1700 edition of the Recherche (which contains a revised version of Des lois) that Malebranche admits that Descartes’ conservation law is false.