Mental causation I
Hypotheses about what people believe and desire greatly facilitate the prediction of their behaviour. That is common ground. And that is where the common ground ends, I fear. Some hold that the common ground fact about prediction exhausts what little truth there is in the view that what we believe and desire explains behav iour; some hold that what we believe and desire explains behaviour, but without doing so causally; and some, the majority, hold that what we believe and desire causally explains behaviour, while differing markedly among themselves over the role of mental properties, and especially the role of the contents of belief and desire, in the causal explanation of behaviour. I will restrict myself to the range of opinions among the majority. I will pre sume a basically realist position that insists that what is believed and desired causally explains behaviour and I will focus on the issues that arise under that presumption. 1
The differences among the majority have many sources, but an important one is a fundamental disagreement over the significance for the debate over mental causation of the causal explanations of behaviour offered by the physical sciences. I start with this issue, and then, armed with a certain view on it, return to the debate over the place of what is believed and desired in the causation of behaviour. The debate over mental causation is not, of course, merely over the causal role of belief and desire with respect to behaviour; other mental states make their entries and exits, as do connections between mental states. But in the interests of keeping a huge topic manageable, I will be focusing in the main on the connection between behaviour and what is believed and desired.