Brain Belief

Brain Belief

We have beliefs about our mind, but do we have beliefs about our brain?[1] That is, do we have beliefs about our brain without knowing anything about our brain? To be more precise, we have de dicto beliefs about our mind, but do we also have de re beliefs about our brain? If I now believe de dicto that am in pain, do I thereby have a belief de re about my C-fibers? Do I have a belief of my C-fibers? This result is easily secured by invoking the identity theory: if my pain is identical to my C-fibers firing, then I must have a belief of my C-fibers. If I have a belief about x and x is identical to y, then I have a belief about y. I may not know that I have this belief, but I do: you can have a de re belief about something without knowing you do. You might be quite surprised to discover that you do. You might even deny that you do, but you do as a matter of fact—you can have beliefs about things you don’t think you have beliefs about. Concerning x you believe quite a lot, while being unaware that you do. Such is belief de re. Thus, you can believe things of the brain without realizing you do, if certain identities hold. The dualist can have beliefs about his brain in believing he is in pain without accepting that his mind is his brain. The facts determine what his beliefs are about de re not his beliefs about the facts. The truth of the identity theory gives us de re beliefs about the brain, assuming its correctness.

Does anything else? Now we enter tricky territory. Not dualism, to be sure: it doesn’t follow from having a belief about an immaterial substance that you have a belief about a material substance merely correlated with it—any more than having a belief about eggs entails having a belief about chickens. Distinct entities don’t generate de re beliefs. But does having a belief about x entail having beliefs about parts of x? I won’t go into this fully but will limit myself to the following proposition: what causally controls a belief generates de re beliefs about it. You have de re beliefs about the cause of your de dicto beliefs: Hesperus and Phosphorus, Superman and Clark Kent, water and H2O, heat and molecular motion. We need not assert identity theories in all these cases to see that what causes one de dicto belief causes the other de dicto belief. Accordingly, if the brain causally controls the formation of de dicto beliefs about the mind, then it is an object of de re belief. C-fiber firing causes me to believe I am in pain; therefore, I have a de re belief about C-fiber firing. Thus, for any de dicto belief about the mind that I have, I also have a corresponding de re belief about my brain, concerning the physical correlate of the mental state in question. This is so whether or not we subscribe to an identity theory. That is the simplest case, but the point generalizes. I therefore have a great many de re beliefs about my brain (granted the causal claim).

I can imagine someone objecting that this conclusion is so implausible and abhorrent that it can be used as a stick with which to beat the materialist. “Look what happens when you go material on the mental! Only dualism gives right result.” I grant that the conclusion is somewhat counterintuitive and not entirely comprehensible, but I think this is because of the nature of the mind-body problem: we can’t see how the material can constitute the modus operandi of the mental. So, we find it hard to accept the kind of intimacy that would ground the move from the de dicto belief to its de re counterpart: how can what is (de dicto) about this lead to being (de re) about that? We have a kind of cross-category implication from the de dicto to the de re (this is not like Hesperus and Phosphorus). I therefore think that the implication should be accepted, despite its apparent oddity. We are full of brain beliefs de re (and some de dicto beliefs if we know a bit of brain science). We perceive the brain de re and we also have beliefs about it de re. It is an object of de re cognition. We are not as far away from our brain as we might suppose. It’s right there in our head and we have many attitudes towards it (even if we don’t know that).[2]

[1] This paper should be read in conjunction with “Brain Perception”.

[2] Actually, the existence of de re belief in general is quite remarkable: it enables the mind to reach beyond its own resources, instead of being locked into them. You can’t have de re beliefs while being a brain in a vat; you need an outside world to cooperate. This confers a degree of externalism on belief; de re belief is definitely not in the head. Nor is the existence of de re belief guaranteed by de dictobelief; there could have been the latter without the former. Belief-of is a special species of belief. It is the world hooking up with the mind, or the mind hooking the world. It straddles mind and world. Would knowledge be possible without it?