ABSTRACT
Though I mostly agree with what I said in “Sensations and Brain Processes” there are some minor changes and some elucidations that I should like to make.
Experiences (havings of sensations and images) seemed to be particularly recalcitrant to the behaviouristic approach of Gilbert Ryle, which I had previously espoused. When I wrote the article in question I still thought that beliefs and desires could be elucidated wholly in terms of hypothetical propositions about behaviour. I soon got persuaded by D.M. Armstrong that we should identify beliefs and desires with mental states which are contingently identified with brain states. I would have eventually come anyway to such a view because of my general realism and worries about the semantics of the contrary to fact conditionals that play an essential part in a behaviouristic analysis. Beliefs and desires raise questions about intentionality. I can desire a unicorn but there are no unicorns to be desired. This is very odd. I cannot kick a football without there being a football to be kicked. Also I cannot kick a football without kicking some particular football. I can desire a bicycle but no particular one: any decent one will do. So “desire” does not work like “kick.” The best way to deal with this seems to be Quine’s: say something like “believes-true S” and “desires-true S” where S is a sentence. The sentence serves to individuate a mental state (brain state). Or I could use a predicate in the case of “I desire a unicorn”: “I desire-true of myself ‘possesses a unicorn.’” (Unicorns may not exist but the predicate “possesses a unicorn” does. I shall not attempt here to defend this account against various objections that might come to mind.)
Another place in which I was too behaviouristic was in my account of colours. I would now identify the yellow colour of a lemon with a state
between physicalist and non-physicalist accounts) contingently identified with a physical state, admittedly a highly disjunctive and idiosyncratic state, of no interest presumably to (say) Alpha Centaurians who had very different visual systems, but a physical state nevertheless. Still, this physical state is identified by the discriminatory reactions of normal human percipients in normal light (e.g. cloudy Scottish daylight). See “On Some Criticisms of a Physicalist Theory of Colours” in my Essays Metaphysical and Moral (Oxford: Basil Blackwell, 1987).
