Blogging Alex Rosenberg's The Atheist's Guide to Reality, Chapters 7 & 8

There doesn’t seem to be much to say about Chapter 7. Taking heed of scientific knowledge of the human mind/brain, including what it reveals about the fallibility of introspection, does significantly reshape our image of what we are. (I find the degree to which our minds are modularized and its modules encapsulated the more radical discovery.) But Rosenberg’s quick move from the fact that introspection is not infallible to the conclusion that it is not reliable is a bit much. Even when an apparent way of knowing fails in some dramatic way, as in the case of blindsight, this does not justify the inference to unreliability. “If it can fail in this way then it must be overall unreliable!” Reliable ways of knowing may come up against unexpected limits. By analogy: it was extremely surprising news when Russell in 1902 wrote to tell Frege that the set theory in which he sought to ground mathematics is inconsistent, or 30 years later when Gödel proved that any formalization of arithmetic is incomplete. That whatever cognitive mechanism underlies mathematical intuition is not infallible is a conclusion in some ways as surprising as the discovery that introspection can fail in spectacular ways. But no one draws from this the conclusion that it is not a reliable means to obtain knowledge. Nor, when it comes to it, does the fact that we are subject to visual illusions–ones that persist when we know they are illusions, a manifestation of perceptual encapsulation–imply that vision is not a reliable way to know.

Chapter 8 is a different story:

Of course: no physical thing inherently means (represents, is about, etc.) anything, i.e., it’s not about anything in virtue of its intrinsic physical features. From this truism Rosenberg infers that no physical thing is about anything. He is entitled to this inference only if it is also true that if a physical thing is about something, then it is in virtue of its intrinsic physical features. A physical thing also has non-intrinsic properties, its various relations to other things. Among these are causal relations. It exists as an effect of other things, and other things exist as its effects. In a particular setting it plays a characteristic causal role: it has typical causes and effects. These causal relations are, of course, manifestations of the laws of physics recruited by natural selection in the construction of brains that navigate organisms through their natural and social environments. There is, say, a neural state typically caused by there being a cat in the vicinity, and this state in turn has, in conjunction with other mental states, typical effects. There is a mental state in Karen caused by the cat being on the table, via her visual system, and this state, together with Karen’s desire for the cat not to be on the table, causes the behavior that consists in Karen evicting the cat from its illicit location. Whatever plays this causal role in the economy of the nervous system, irrespective of its physical constitution, is a representation of the cat. This is how mere physical things can be about things.

What seems very tendentious is the claim that this is not an account of how neuronal things can be about things, but the revelation that they are not about anything. A familiar pattern: start with a folk-concept of something, show that nothing in the world where physics fixes all the facts perfectly answers to it, and announce that nothing answers to it. The alternative, that we have discovered that the concept needs revision, remains out of sight. The reiterated assertion that nothing in the brain can be about anything invites us to wonder what is being denied. The causal role theorist claims that chunks of grey stuff are about something, but that this is not in virtue of their intrinsic properties, Rosenberg says, “That’s not genuine aboutness!” But why isn’t it? What is it that those clumps of grey matter lack that precludes them being about anything? We’re entitled to ask Rosenberg to complete the sentence, “A chunk of grey stuff would be about something if_______.” Is there no way to finish the sentence because what’s required is some non-physical property? I suppose that he would regard it as equally obvious that if there were a non-physical thing, it could not be about anything either. So is it that there’s no way to complete the sentence because the concept of aboutness is incoherent; nothing can be about anything just as nothing can be a square circle? But then there’s a burden to reveal the contradiction allegedly implicit in, “That clump of neurons is about Paris.” There’s no sign of this burden being discharged.

If there’s an argument lurking here, I imagine that it’s something like:

Aboutness must be either intrinsic or derived.

Nothing possesses intrinsic aboutness.

Something possesses derived aboutness only if something else possesses intrinsic aboutness.

Therefore: Nothing possesses aboutness.

There is, I suppose, some intuitive appeal to the third premise. But is it really true? The idea is something like: the word “cat” is about cats, but not in virtue of any intrinsic characteristic; its aboutness derives from human beings, who establish the convention that makes it about what the idea cat in their minds is about, and that is about cats not derivatively but intrinsically. But then we’re left with the truistic: nothing is about something by convention unless something else is about something not by convention. Clumps of grey matter in the brain, like the word “cat,” lack intrinsic aboutness, but this does not imply that any aboutness they could have must be conventional. It might simply be natural, having its antecedents in neural structures like those of the sea slug, in which there is no good candidate for being a mental representation. Between the sea slug and humans there need be no sharp phylogenic line where aboutness appears. Eventually, though, we can economically explain a creature’s behavior only by describing some of its neural structures as representations. That which is about something arises gradually from what is not about anything; in this sense, its aboutness is derived, but not from something that has intrinsic aboutness.

This said, it might be that the upshot of all this is that we’ve found that the concept aboutness (intentionality, representation, meaning, etc.) is useless; on analogy, we’ve come around to the view that the concept witch has no application in the real world. But this strikes me as implausible. Representation, e.g., seems to me precisely how we want to describe that mental state in the mind of Karen caused by the cat and causing her cat controlling behavior.