In his defence of the identity theory, Professor Smart has attempted to show that reports of mental states (for example, sensation reports) are strictly topic-neutral. If this were the case then it would follow that there is nothing logically wrong with the claim that the mind is the brain (and nothing more) or that mental states are really nothing but brain states. Some phillosophers have argued that a fundamental objection to any form of materialism is that the latter makes an obvious logical blunder in identifying the mental with the physical. This is the view that dualism is enshrined in our language. If this is true then of course statements such as ‘the mind is actually nothing but the brain’ and ‘mental states are really nothing but physical processes’ would be quite unacceptable on strictly logical grounds. Smart's claim that talk about mental states is topic-neutral, however, appears to exempt materialism from such objections. The question is, does it? That is to say, are sensation reports and the like topic-neutral in the required sense? Are they analogous in principle to statements of the form ‘someone is in the room’? Smart's point is that expressions such as ‘someone phoned: it was the doctor’ are logically similar to those of the form ‘I am having a red after-image: it is a brain process.’ ‘Someone’ is not logically equivalent to ‘the doctor’ (and it even sounds strange to say ‘someone is the doctor’), but it may, of course, be true that the doctor is the someone who phoned. Does this analogy hold and is it correct to say that sensation reports and mentalistic expressions in general are topic-neutral, that they refer only to experienced ‘somethings’? Smart's claim runs as follows:

When a person says, ‘I see a yellowish-orange after-image’, he is saying something like this: ‘There is something going on which is like what is going on when I have my eyes open, am awake, and there is an orange illuminated in good light in front of me, that is, when I really see an orange’. (And there is no reason why a person should not say the same thing when he is having a veridical sense-datum, so long as we construe the ‘like’ in the last sentence in such a sense that something can be like itself.) Notice that the italicised words, namely ‘there is something going on which is like what is going on when’, are all quasi logical or topic neutral words. This explains why the ancient Greek peasant's reports about his sensations can be neutral between dualistic metaphysics and my materialistic metaphysics. It explains how sensations can be brain processes and yet how a man who reports them need know nothing about brain processes. For he reports them only very abstractly as ‘something going on which is like what is going on when…’ Similarly, a person may say ‘someone is in the room’, thus reporting truly that the doctor is in the room, even though he has never heard of doctors.