Why a theory of inner wiring can’t say what it is like to see

Every conscious experience points at the world. You see a red apple, you fear the dog in the yard, you think of a friend’s face, and each time your mind reaches outward and takes hold of something beyond itself. You should find it self-evident that your states are always about the world, which includes not only your surroundings but also your body. This “aboutness” runs through the whole of the mind. It is called the mark of the mental, and it turns out to be the key to everything that follows.¹

Now set that beside one leading theory of what a mind is.² The mind, according to this theory, is what the brain does, not what the brain is made of. What matters is the wiring — the working parts and the particular jobs they perform. An input comes in, the inner states pass it along, and an output goes out; get that pattern right, in flesh or in silicon, and you have a mind. The material does not matter; only the pattern does.

Call this view functionalism. A great deal of it is right. The brain really does work like a machine, its parts really do have jobs, and you really could build the very same organization inside a robot. So far the theory stands on solid ground.

But look where it draws its line. It draws the line at the skin, speaking only of abstract inputs, outputs, and inner states, all of them inside the head. The actual physical world outside never enters the story; the theory maps the wiring and then stops. And there is the trouble. The mind points at the world while the theory stays in the head, so it leaves out the one thing that makes a thought a thought about the world. It keeps the reaching and loses what the mind is reaching for.

This is exactly why the theory gets stuck on the hardest question about the mind — consciousness itself, the feel of things. What is it like to see red, or to taste salt? No functionalist wiring diagram seems to capture it, and the feeling slips through the net every time. So some philosophers conclude that the feeling must be some additional inner glow, sitting on top of the wiring — a private, personal light that science may never manage to reach.³

I am convinced it is nothing of the kind. The feeling is not an extra thing hidden away inside you; it is the world your mind was pointing at all along. Think it through. What is it like to see red? It is like seeing a red thing — a ripe tomato, a stop sign, fresh blood. Now take the world away and ask what remains. Nothing remains. Of course nothing feels like anything once you have thrown out the very thing the seeing was of. You did not discover a gap in nature. You left the world out.

So the repair is simple: put the world back. The red you see is a real feature of the thing in front of you — the particular way its surface throws back the light.⁴ Your mind reaches for that feature, and the feel of red comes down to that reaching, aimed at that object of that color.⁵ Change the color out there and you change the experience of it; hold that color steady, and the feeling holds steady too.

And here is the turn that should surprise you. Putting the world back makes the mind more physical, not less. The world is no ghost. It is more plain, ordinary stuff — the surfaces and light and things a living body has to deal with, all lying just past the skin.

Functionalism was never too bold. It was too shy. It shut the mind up inside the skull, and then could not explain a thing that lives half outside it.

The rehabilitation of functionalism comes at a price, however. Once you let the world back in, you give up the tidy dream that a mind is just a program — a pattern you could run anywhere, in any box, cut off from everything. The system needs a real body, in a real world, and a real history of dealing with the things in it. You cannot buy that with clever code in a sealed box. So the very move that saves the theory breaks its boldest and most hyped AI promise of conscious computers.

But perhaps all is not lost. Perhaps we can build a robot that lives out in the world, embodied and grounded in it, such that it can have a mind directed toward it, with mental states about it. The question then becomes what do we mean by such a robot that lives out and about in the world. I explore this question in my book.

-gts

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This essay is part of Mind, Matter, and Meaning, an AI-assisted philosophy project by Gordon Swobe exploring consciousness, meaning, and artificial minds. Learn more about the project and read the book.

Notes

1. The “aboutness” of the mind — its directedness at objects and states of affairs — is Franz Brentano’s mark of the mental, usually called intentionality. Every thought is a thought of something; every fear, a fear of something. ↩
2. Functionalism: the view that a mental state is defined by its causal role — its inputs, its outputs, and its relations to other states — rather than by the physical stuff that carries it. Classic statements come from Hilary Putnam; the sharpest early pressure on it, from Ned Block (“Troubles with Functionalism,” 1978). ↩
3. The “hard problem of consciousness” (David Chalmers) and the “explanatory gap” (Joseph Levine, 1983): the felt quality of experience seems to resist any functional or physical account. The claim here is that the leftover is not an inner extra but the omitted world — a gap in our way of describing the mind, not a crack in nature. ↩
4. On color as a real, physical property of a surface — a reflectance-type — see Alex Byrne and David Hilbert, “Color Realism and Color Science” (Behavioral and Brain Sciences, 2003). The color you see belongs to the thing, not to an inner screen. ↩
5. The positive view: phenomenal character consists in the world-directed representational content of experience (Michael Tye, Fred Dretske). The fuller argument — which works through Chalmers’ fading- and dancing-qualia thought experiments and answers Ned Block’s Inverted Earth — appears in the companion essay, “Absent Qualia, Fading Qualia, Dancing Qualia: The World Functionalism Leaves Out.” ↩

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