The Efficacy of Content: A Functionalist Theory

Not all of the problems of mental causation are problems about the mind. Recent work on mental causation has been pre-occupied with a problem which arises if we accept that the physical world is causally closed or ‘complete’ — i.e. that every physical effect is completely fixed by its physical causes alone — and that there are mental causes of physical effects too. How can mental causes have physical effects if those effects are not overdetermined by their acknowledged physical causes, which most parties agree they are generally not? This problem is acute in contemporary theories of mind because they typically deny most versions of a thesis that would solve the problem: an identity theory of mental and physical causes.1 If mental causes are not identical to physical causes, and there is no massive overdetermination, then it seems we must reject either the causal closure of the physical world or the existence of mental causation.