Behaviourism and Functionalism

What exactly is the connection between mental states and behaviour? The connection, it seems, is an intimate one; philosophical behaviourism makes it out to be a very intimate one.

There are various forms of behaviourism, more or less extreme. But roughly speaking what they all claim is this: somebody is in pain, or believes that p, or is jealous, or whatever, just in case he or she is behaving in a particular way – or just in case he or she is disposed to behave in a particular way. (That ‘or’ already signifies an important difference of approach.)

Now a certain queasiness about behaviourism has been expressed in the objection: ‘But surely pain (or whatever) can’t just be behaviour, or a behavioural disposition? Isn’t the behaviour (or the disposition) produced by the pain? And so isn’t the pain itself in some sense inner?’

The traditional notion of the ‘inner’, associated with such philosophers as Descartes, has to do with the subject’s alleged special and privileged access to his own mental states – and this notion has tended to go with dualism about mind and body. But more recent philosophers have been keen to hang on to the notion of the inner while rejecting traditional dualism – in particular, functionalists.

The main respect in which functionalists differ from behaviourists is in their saying that someone is in pain (or whatever) just in case he or she is in that state which is in fact typically caused by certain things, and which typically produces certain types of behaviour. Again, there are variants of functionalism, but this will do as a broad characterization.

Actually, there are two differences to notice here between functionalism and behaviourism. One is that functionalists mention causes, as well as behaviour; the other is the reference to a state of the subject, productive of that behaviour. It is this state that is typically spoken of as ‘realizing’, or indeed as ‘being identical with’, the subject’s mental state on a particular occasion; and it is this state that performs the role of an ‘inner state’ – ‘inner’ in quite a literal sense, now, since it is usually taken to be a brain state or some such internal state of the creature in question.