Physicalism

A physicalist would say, of course, that the condition of 'seeing a bright light' (however intentional) would have to consist in some set of physical facts - e.g. about my nervous system, about some interaction between photons and my retina, about some set of brain activities.

This has to be wrong for two reasons:

(1) Suppose a physicalist specified such a set of conditions, and then met a person who was demonstrably in the relevant physical state but denied seeing a bright light. Would the physicalist have to say they were lying and/or mistaken?

Not necessarily: they could say that their specification had failed an experimental test, and some improved specification was required. However, this process of improvement would have to come to an end, in order to save the physicalism - and it would have to be an end which did not depend on testing against reports of seeing bright lights. At some point, the physicalist account would have to be more reliable than the intentional report - it would have to provide a basis for saying that the intentional report was dishonest or mistaken.

We do, of course, often decide that people are being dishonest about intentional states - and we may also conclude that they have made mistakes in the way they express them. However, any decisions of this kind are subject to Kripkean ambiguities and Davidsonian interpretive choices. It can never be a matter of absolute fact that an intentional report is dishonest or mistaken - there will always be some interpretation under which it can be saved. But when we reject these interpretations (as we often do) we are making a normative choice.

Some religious people, for instance, claim to believe remarkable eye witness accounts of miracles in order to save the integrity of their saints. For the physicalist to insist that my brain state plus certain environmental factors indicate that I am seeing a bright light - whatever I may appear to say about this on my own behalf - they are making a choice of this kind.

From this perspective, physicalism - along with all the other metaphysical foundationalisms - becomes a position adopted through interpretive choice. I guess this is what Simon Blackburn has in mind when he talks about quasi-realism. We should talk as though we are realists. But then why not quasi-idealism? Apart from making the computations more complicated there doesn't seem to be much to object to in it ...

A really committed physicalist might deny that the examples given above are coherent - claiming that someone in the appropriate physical state would also, necessarily, say appropriate things (utter appropriate noises?). But this just skips the demonstration - in order to show that physical states and intentional states go together, they need to be separately specifiable. If they can't be, then the physicalism becomes contentless.

(2) OQ again: For the physicalist, physicalism itself (the set of beliefs comprising physicalism) would have to be reducible to some physical state of affairs. To be a physicalist is to be in an intentional state - of believing that intentional states can be reduced to physical states - that must, therefore, itself, be reducible to a physical state.

One problem with this (related to (1) above) is that it's hard to see how a physical states can be right or wrong - it's just a physical state. Also, we'd need - in principle - to be able to specify this state without begging the question (e.g. by calling it 'the state of being a physicalist'), and without being diverted by accidental equivalences (e.g. if all physicalists, and no non-physicalists, happened to be tall & have large noses, for instance). We'd also have to accomodate the possibility (as in (1)) of people claiming to be physicalists - appearing to know the arguments etc. - but being wrong, because they were in an inappropriate physical state.

A more serious problem, though, is the general OQ problem: if having a true belief about X is to be in a certain physical state, then there must be a physical test for the truth of such a belief. In particular, there must be a physical test for the truth of physicalism. If there isn't such a test - if there is some non-physical test for the truth of the belief - then physicalism is incomplete. But to insist on there being such a test is to beg the question - it's simply to insist that physicalism must be correct.

N.B. - An argument against physicalsim is not automatically an argument for some other metaphysical substrate (idealism, for instance). All these metaphysical foundationalisms are equally vulnerable to similar kinds of arguments.

Also, it is perfectly possible that there are no other fundamental objects or forces in the world beyond those discovered by physical science - in the sense that we won't find any there, no matter how hard we look. (There are no fairies at the bottom of the garden).

However, this isn't sufficient for a physicalist account of intentional states.

Imagine an artist making a representation of a face: there must be a physical medium for this, but the choice of medium is only marginally relevant to the description of the activity. No list of media and of related techniques could give an exhaustive account of this activity, because some new medium - holography is a recent example - might come along in which the intentional act of 'making a representation' could be carried out.

This problem becomes worse if you think of 'making a representation' in terms of 'making a good representation' - i.e. making a representation that is recognisable, or apt.