Philosopher Colin McGinn says he is “going to adumbrate a new theory, quite an eye-stinging one. It says that you perceive your own brain.” Consciousness is perceiving your own brain. This means, to be more specific, “pain is the perception of C-fibers firing. It isn’t C-fibers firing themselves, but the perception of that.^[1] The relation between pain and C-fibers is like that between seeing a dog and the dog: they are numerically distinct and yet closely entwined. The sensation of pain has a perceptual object and it’s in the brain. And not just pain: visual sensations, too, are perceptions of brain states (perturbations of the occipital cortex). When you see a dog, you also see your brain, or a bit of it. In fact, all consciousness is brain perception” (McGinn, 2025f, following).

Even all thinking, McGinn says, “is perceiving (sensing) your own brain. This isn’t because all consciousness is a brain state; it’s because all consciousness is brain perception. To put it with maximum provocativeness, consciousness is brain awareness—awareness of the brain. All consciousness is consciousness-of… the brain. This can be stated as an identity theory: mental states are identical to perceptual states of brain awareness. I don’t say only such awareness; rather, they are brain perception plus awareness of other things (if they have intentionality, that is). They have a kind of double intentionality: of the out-there and the in-here. You sense your environment and you sense your own body in the person of the brain. You have a dual awareness. If your mental states are states of your brain, then we can say that your brain senses itself: pain, say, is a state of your brain that is identical to a perception of your brain. On the other hand, if pain is a state of an immaterial substance, then it is a state of an immaterial substance that is identical to a perception of your brain. Thus, your mind has a relational structure: it stands in the relation of perceiving to your brain—as well as to other objects. If you have a tactile relational perception of an external object, you also have a tactile relational perception of your brain (the tactile part of it)—you touch your own brain, to put it crudely.^[2]

McGinn addresses what one might sense as an obvious problem with his theory: “people can have minds without knowing much if anything about brains. For surely, we don’t perceive anything as a brain when we enjoy ordinary experiences. I don’t feel that my C-fibers are firing when I am in pain. But that is not what the brain perception theory says; it says only that I am aware of my brain, not that I am aware that my brain is doing such-and-such. The awareness is de re not de dicto: it is true of my brain that I am aware of it—not that I am aware of it under a brain description. Perceptual statements have a de re/de dicto ambiguity, and the brain perception theory endorses only the de re reading. You can be conscious of something x that is actually F without being conscious that x is F. Compare ordinary visual perception: you can see (be looking at) an object that is in fact a block of atoms without seeing it as a block of atoms. We are aware ofcollections of atoms all the time but not as collections of atoms. We can be aware of objects that satisfy all manner of descriptions without knowing these descriptions or otherwise mentally representing them…. Thus, the brain perception theory is only claiming that we have de re perceptions of our brain states; it isn’t that we get mental images of our brain whenever we have an experience—or that our brains even cross our minds” (McGinn, 2025f).

How does McGinn defend the idea that the relation between mind and brain is one of perception? “One reason is that we get a nice uniform account of the nature of the mind: all mental phenomena are perceptions of the brain—this is what they are (the essence of the natural kind)… But second, and more subtly, it is part of the phenomenology of experience to sense an inner reference: we feel that our mental states are somehow inner. We certainly don’t feel them as outer, and I don’t think we are neutral on the question; we feel that they belong with us, internally. I don’t think my mental states might be outer; they strike me as definitely inner. But what kind of inner?”

McGinn sets a contrast with the “inner” as “an immaterial substance—the Cartesian ego.” If that were so, he says, “we would be in a perceptual relation to the states of such a substance, according to the perceptual theory of the mind. But we have discovered that it is the brain that houses and services the mind, so that entity is a better choice of perceptual object. If mental states are perceptions of something internal, as they seem to be, then the brain is the best candidate.”

Going further, McGinn asks, “But why suppose that these objects are perceived? That turns on what perception is, a question hitherto left dangling. The answer, I suggest, is that perception is basically a matter of a response to a stimulus—an action of registration or tracking or indicating. The mind is tracking the brain, recording its doings; the two are reliably correlated. The mind, we might say, senses the presence of the brain; not de dicto, to be sure, but de re. The brain causes the mind to respond in certain ways, such that you can read one off from the other. The mind perceives the brain in the sense that it is sensitive to what the brain is up to—as the senses are sensitive to what the environment is up to. To a well-informed intelligence, the mind would provide information regarding the brain. The mind senses changes in the brain, but only as changes in something internal, not as neurological changes—which they actually are.”

Assuming this idea sinks in, McGinn argues that “it seems very natural to speak of the mind as perceiving the brain; it is keeping tabs on the brain, resonating to its activities, albeit in a sort of code. Consciousness acts like a secret code for the brain, a kind of translation. The brain is encoded in the mind, as the external world is encoded in sensory experience. Thus, it is natural to speak of mental states as perceptions of the brain—ongoing (partial) reports on it. Pain is the code word for C-fibers firing, if only we could crack the code.^[3] If one day we manage to decode the code, we will naturally think of our experiences as messages from the brain; and we might become very adept at this and regard consciousness as we now regard vision in relation to the environment. The concept of perception is fairly elastic, so we might find ourselves happily using it to talk about our states of mind (‘I felt my frontal cortex to be unusually active this morning’, ‘My hypothalamus feels slow today’). We might even become able to selectively attend to certain regions of the brain, as we can with our senses.”

According to McGinn, how should we think about a mental state? “It points in several directions. It points to the external world—this is intentionality: there is a dog over there. It points to the internal world of the brain—this is brain perception: my C-fibers are firing. It points to behavior—this is action: I am about to throw a ball. The mind is about things; it is brain-sensitive, and it is functionally active. Two of these features are very familiar to us. I am adding a third feature: it is brain-perceptive.”

McGhie concludes by finding it “fascinating that the mind is a window onto the brain, another way to ‘see’ the brain. When I see a tree, I can sense my brain fizzing away just below the surface (or I fancy as much). I feel that I can focus on it, get to know it better. I feel closer to my brain now, less alienated from it. My phenomenology has shifted. I have become more brain-centered, existentially^[4] (McGinn, 2025f).

Footnotes

[1] It should be noted that this theory is compatible with materialism: the act of perceiving C-fibers firing could be a brain state distinct from C-fibers firing. Pain would then be the brain state of perceiving the brain state of C-fibers firing—a kind of combination of the two.

[2] I say “touch” because a tactile sensation is arguably sufficient to qualify a sense as the sense of touch; you don’t need a physically touching body.

[3] We could devise a code in which causing you a (mild) pain acts as a sign that there is danger nearby. In terms of information theory, pain carries the information that one’s C-fibers are firing (makes it more probable).

[4] It is interesting to ask, in a science fiction spirit, what human life would be like if we knew the brain state corresponding to a given mental state, for all mental states. It would make our consciousness pretty jammed, I’m sure; maybe we are lucky not to perceive our brain in the de dicto way. It’s really best to minimize the content of consciousness for all practical purposes. There might I suppose be a brain pathology in which someone did have sensations of his brain when he experienced anything (The Man Who Mistook His Wife for a Brain).