John Heil says that instead of talking about different causal interactions between minds and world, why not talk about 'different contexts’: He writes:
"The face, located in a depiction of merry party-goers is a happy face. The very same face located in a scene of devastation and suffering is evil. The face’s being happy or evil depends, not on intrinsic properties of the face (or at any rate not wholly on these), but on the context in which the face appears. If you vary the context, you change the face." (424)
Again, the intrinsic properties of the face don't change whether or not it's seen as happy or seen as evil. The only things that change are the contexts. The change of context determines how we interpret the face regardless of the fact that the face hasn't actually changed at all.
This is clearly an analogous with what happens with the mind.
In both cases the Cartesian or internalist mind may not change. However, if the contexts of the minds or mind change, then so too does its mental content. More to the point, the change in context will determine and fix the meaning of the mental content. Though, again, neither mind is required to know that the context has in fact changed. Nevertheless, if it has changed, then it will change the meanings of the words and sentences expressed by such a mind or by such minds.
So meaning-in-mind depends on the mind’s causal relations to things outside of mind. And if that's the case, we can't really talk about ‘meaning-in-mind’ because meanings are partly determined or fixed by things outside of the mind. Perhaps we can't even talk, then, about the ‘outside’ of the mind or about ‘external reality’ if the so-called ‘internal’ reality wouldn't even be the way it is without an ‘external reality’. Perhaps the internal/external dichotomy simply breaks down, at least when it comes to talk about the mind’s relation to the world.
This, if it's true, is a sharp rebuke to traditional (epistemological) scepticism.
Why is that? Because scepticism "presumes a sharp division between our thoughts and the world of which those thoughts are directed" (424). As I've said, perhaps there would be no thoughts about the world if it were not for the world in the first place. More strongly, perhaps there would be no thoughts about X, Y and Z in the world , if X, Y and Z hadn't already determined or fixed these thoughts about themselves.
The sceptic asks us:
"What gives us the right to believe that what we think is the case is the case?" (424)
The externalist will simply answer:
"If the contents of our thoughts depend on how things stand in the 'external world', there can be no question of our being dramatically deceived." (424)
Our thoughts are determined or fixed by how things stand in the world. We wouldn't have these thoughts about the world if the things the thoughts are about didn't exist and they didn't have a causal effect on the contents of our thoughts (about them).
Does it follow that we can't be deceived?
Perhaps we can say that the world, or things in the world, do indeed determine or fix the contents of our thoughts. Does it follow, however, that our thoughts, or representations, correctly represent the way the world actually is even if the world has determined and fixed the content of our thought and has even given us these very thoughts in the first place?
We can accept this causal determination of mental content or thought; though causation in and of itself won't guarantee the correctness of our thoughts or representations of the world. As Davidson said (in a slightly different context): causation doesn't come under a description. Causation fixes or determines our thoughts ; though it doesn't determine their shape, as it were. It's responsible for mental content; though not for the shape of that mental content. Causation itself is neither thought nor mental content; just as it's not itself either description or explanation.
Why does it follow that because of the fact that we wouldn't have thoughts about the world in the first place if it weren't for the world itself, that how we think about - or represent - the world will be true of the world? Causal interactions can't be enough to silence the sceptic. All that we can say, however, is that there must be a world because we causally interact with it and those causal interactions determine or fix the thoughts or mental content; though they don't in and of themselves determine their shape.
The world must exist; though our thought and representations of the world may be radically inaccurate. Causation alone doesn't guarantee otherwise. Thus the sceptic is partly beaten in that the existence of the world is established. However, the externalist hasn't established the actual shape of the world. Perhaps this is a pyrrhic victory on the externalist’s part. Perhaps it's also a pyrrhic victory on the sceptic’s part.
The problem with these conclusions is that many, or all, externalists reject representations, or at least the idea of mental representations precisely because of their externalist position. The question is:
Why do externalists, and other philosophers of mind, deny the existence of mental representations?