Occasionalism

2. Early modern occasionalism

Occasionalism in modern philosophy took its ‘occasion’ from the problems over causality that arose in Descartes’ philosophy (see Descartes, R. §§8, 11, 13). (Not only the problem of mind–body interaction, however; causal interaction among bodies was also problematic for Descartes.) Descartes himself had tendencies towards occasionalism, and this view was adopted by the Cartesian philosophers Louis de La Forge and Géraud de Cordemoy. Arnold Geulincx may have been the first to state an important principle that is also found, in modified form, as a premise in arguments concerning causation given by Malebranche and Hume. The principle states that something cannot be done unless there is knowledge of how it is done; more specifically, people do not do what they do not know how to do. This quickly disposes of the contention that the mind causes bodily movements; in order for the mind to do this, we should have to know how to control the physiological processes involved in making such movements – the firing of neurons, for instance. Clearly, however, we do not know this. The principle also excludes causal efficacy for corporeal bodies, since these bodies obviously lack knowledge of how their supposed effects are produced.

Nicolas Malebranche (§4) was clearly the most significant of the modern occasionalists. Basing his argument on the supposed impossibility of mind–body interaction, he writes that ‘There is no real relation between one body and another, between one mind and another. In a word, no created thing can act upon another by an activity which is its own’ (1688: 4.11). He argues, like Geulincx, that in order for our minds to be able to move our bodies we should have to understand, in full anatomical detail, how this is done. He also argues that God’s causality pre-empts, as it were, any possible causality among creatures. No creature can exist unless God, by ‘continuous creation’, wills that it should exist. But in willing that a chair (for example) should exist, God must will that it exist in some particular place, in some particular state of motion or rest, and so on. Clearly, no created power (assuming there to be such) can cause the chair to be at rest or in motion unless God wills that it be so. But if God does will the chair to move, then necessarily it moves; there is nothing left to be done by any created agent. Thus, ‘God communicates His power to created beings only because He has made their modifications the occasional causes… which determine the activity of His volitions in consequence of the general laws which He has prescribed to Himself’ (1688: 7.10).

Occasionalism did not persist for long as a widely accepted view. But the influence of Malebranche was considerable, and is still felt today through Hume, many of whose sceptical arguments concerning causation derive from Malebranche.