The problem is straightforward:
- Consciousness is either physical or non-physical.
- If physical, we can’t explain the subjective quality of experience.
- If non-physical, we can’t explain how it interacts with the physical world.
- Therefore, ???
First: By “consciousness,” I mean the mind—in Descartes’ terms (page 10), “a thing which doubts, understands, [conceives], affirms, denies, wills, refuses, which also imagines and feels.” Whatever exactly that is.
The puzzle is: What is it, exactly? Specifically, is it composed of matter, like rocks and chairs, or is it something different, something ‘special’? Considering that much of modern religion depends on the idea of an immaterial soul, by which is usually meant (and which always includes) consciousness, it’s an important point.
The problem is simply that there seem to be irresolvable difficulties with both options.
Let’s say consciousness is physical. Perhaps it’s in the brain. In that case, questions come up: What composes it? Those string-like neurons in the brain? The electrical signals between them? Why, then, when I feel something, do I not feel the neurons, the synapses? Or to put it the other way around, how do these fibers and these electrical discharges feel like blue, softness, saltiness? In the philosophy of mind, this is called the qualia problem. I can say everything there is to know, know everything there is to know, about the color blue. I can talk about wavelengths, the eye, the relevant neurons, etc. But unless I’ve actually seen blue, I have no idea what it looks like. If I’m locked in a black and white room like Frank Jackson’s Mary example, I have no idea. If I’m colorblind, I never will. Since I know the physical facts, but not what blue really is, what makes blue what it really is is not, or not just, the physical facts. End of story, it seems.
Okay; let’s say that consciousness is non-physical. Whatever matter ultimate is, we can seem to say with Descartes that it is extended in space somehow, and subject to physical law. That’s what makes something physical. If consciousness is not physical, it is not that. Question: If we feel (consciousness, so non-physical) hungry because the body (physical) tells us, how does it do that? By what means? And when the mind ‘tells’ the body to reach for the cake, how does it do so? “Your notion of the soul entirely excludes extension, and it appears to me that an immaterial thing can’t possibly touch anything else,” Princess Elizabeth says to Descartes in their correspondence (page 1). How could something that doesn’t physically exist, and lacks physical force, move something physical? End of story, it seems.
The puzzle lingers still. It’s not much help to religion, but neither is there a free pass for the scientifically minded physicalist. Perhaps, somehow, one of these simple, straightforward arguments is wrong. Or perhaps the mind (as Maurice Merleau-Ponty held), or the physical world(as Hedda Morsch holds), or both, are more complicated than we suspect.