1. Belief and mental statesDavidson holds that intentional verbs occurring in the form ‘A Vs that p’ signify propositional attitudes. These are, he claims, (i) mental states (MS 160; KOM passim), and (ii) dispositions (FPA 103). Davidson does not conceive of himself as introducing a special technical sense of the common intentional verbs. He insists that ‘the mental states in question are beliefs, desires, intentions, and so on, as ordinarily conceived' (KOM 51f.). Consequently he contends that believing that p is a mental state, disposition or dispositional state. These ontological claims about the nature of belief inform his account of the logical form of belief sentences. I shall address the question of whether believing that p can justly be deemed a mental state, a disposition or dispositional state. Subsequently I shall examine Davidson's account of the logical form of belief sentences.Our concept of a mental state, like so many of the concepts which philosophers treat as categorial, is none too sharply defined. It has a respectable use, which can be described. But, like other such general psychological terms, e.g. ‘mental process’, ‘mental activity’, far from being the ‘hardest of the hard’ - a sharply circumscribed categorial term akin to a variable in a well-constructed formal system — it has blurred boundaries and is elastic. Like all our ordinary psychological concepts, it evolved in order to meet everyday needs. As Wittgenstein observed, ‘The concepts of psychology are just everyday concepts. They are not concepts newly fashioned by science for its own purposes, as are the concepts of physics and chemistry.’Although our ordinary concepts can be replaced by technical ones for specialized purposes, they cannot be abused without generating conceptual confusion and incoherence. If the expression ‘mental state’ is being employed in its ordinary sense, then it is wrong to hold that believing that p is to be in any mental state. If it is being employed in a special technical sense, then those who employ it thus owe us an account of what it means and how it is to be used. This Davidson and the many other philosophers who subscribe to the view that believing is a mental state have not done. Until such an account is forthcoming, one may presume that they think of themselves as deploying our ordinary concept of a mental state. And if so, I shall argue, they are misusing it.
Undercutting Defeat and Edgington’s Burglar
