The Brain-Brain Problem

The Brain-Brain Problem

Time for some conceptual house-cleaning, or furniture-arranging. We have been talking about the mind-body problem all wrong; we need to bring our formulations up to date. We used not to know that the brain is the central mechanism of the mind; now we do. The mind is an aspect of the brain—mental properties are properties of the brain. The self is the brain; mental properties are properties of the self; therefore, they are properties of the brain. There is no mental substance for them to be properties of, and we now know that the brain is responsible for what happens in the mind—for mental events, faculties, etc. There is nothing to prevent us from saying that mental properties are brain properties.[1] We could (and probably should) drop the definite description “the mind”, or “the human mind”, which suggests there is a thing called “the mind” that is not identical to the brain. Let’s get used to speaking of mental properties as brain properties. The brain has many properties—anatomical, cellular, biochemical, electrical, atomic, and mental. The brain is what is consciousness exists in. On the other hand, the body is not strictly part of the problem, if we mean the biological structure in which the brain (and hence the mind) is situated—belly, legs, arms, etc. That may not even exist and we would still have a “mind-body” problem. What we really have is a brain-brain problem: how do some aspects of the brain relate to other aspects of the brain? How do the non-mental aspects relate to the mental aspects? Thus, the problem concerns how the brain relates to itself—what might be succinctly called “the brain problem”. How is what we call the brain possible? Must we be dualists about the brain? Are some aspects of the brain reducible to others? Are some properties of it supervenient on others? Could there be a brain physically just like the actual brain that had only non-mental properties (a zombie brain)? What is it like to have the brain of a bat? Are brains beyond human comprehension? Is the brain a miracle-worker? That’s the way to talk.

It is evident that not all aspects of the brain present a philosophical problem. First, some parts of the brain have no mental aspect, so don’t present a “mind-body” problem. Neurons are not universally mentally endowed. Second, even among those that are correlated with mental properties, there are unproblematic inter-aspect relations. There is no deep problem of relating the gross anatomical architecture of neurons with their biochemical properties. Nor are electrical properties puzzlingly emergent on chemical properties. We have no problem understanding how the shape of the brain arises from its constituent parts. The brain is not inherently a puzzling mysterious place; it’s as transparent as the heart or the kidneys, more or less. Only in one aspect does it present philosophical difficulties—the mental aspect. It is selectively problematic. A subset of its properties (designated “mental”) resist unification with its other properties. We have a partial brain problem not a general one. The brain is only a bit mysterious—though it’s quite a big bit. It’s like investigating the railway system of a country and finding it pretty easy to understand—except when it comes to how (say) people buy tickets. Everything is fairly smooth sailing (the weather is fine) except for where the brain sails into mental waters (then things get stormy). It is, we might say, anomalously problematic. It ought not be problematic at all to a general inspection, but then it suddenly turns opaque. The brain is locally mysterious—mysteriously mysterious, one might say. Why does it turn mysterious only with respect to one of its aspects? Yet it does. We get the possibility of dualism, with zombies and disembodied minds, type and token identity theories, functionalism, panpsychism, and the rest. The brain problem is itself a problem—why does the problem even exist? How did (could) brains evolve from inanimate matter? The mind itself is not such a problem, and the body is intelligible enough, but the mental aspect of the brain is a deep mystery. The brain alone is an enigma, flanked by (relatively) intelligible things (bodies, minds). Our question ought to be “Can We Solve the Brain Problem?” I don’t say this formulation will make it any easier to solve, but at least it frames the question correctly.[2]

[1] Of course, I don’t mean by this that mental properties are reducible to other brain properties (like C-fiber firing); I mean they are already brain properties (like pain). Mental properties could be completely irreducible and yet still properties of the brain. I take no stand on that issue here.

[2] Philosophers don’t usually study the brain as part of their formal training, so are not used to thinking about it. When I first studied it as part of my psychology degree, fifty-six years ago, I was deeply troubled by how the brain relates to consciousness and the mind generally. I think there is an instinctive resistance among philosophers to acknowledging the centrality of the brain to the mind, but this resistance needs to be overcome. The philosophy of mind is really the philosophy of the brain—in its mental aspect. (I am not advocating “neuro-philosophy”.) The brain has a mind as the heart has ventricles. Psychology and philosophy of mind are about this aspect of the brain; physiology is about its other aspects.