A summary of the argument the contemporary Deniers make against conscious experience looks something like this:
- Naturalism entails materialism which entails that all reality is reducible to matter.
- Conscious experience cannot be reduced to matter.
- Therefore, conscious experience isn't real.
- Naturalism is true and it entails that all reality is reducible to matter.
- Conscious experience is real.
- Therefore, conscious experience can be reduced to matter.
Nevertheless, the conclusion of this syllogism only follows if we know that the first premise is true. Strawson seems to beg the question by assuming it is, but that's just a metaphysical preference, a presupposition, an act of faith on his part. It could just as easily be false for all we know since he offers no argument for it.
Here's his own summary of his argument:
Naturalism states that everything that concretely exists is entirely natural; nothing supernatural or otherwise non-natural exists. Given that we know that conscious experience exists, we must as naturalists suppose that it’s wholly natural. And given that we’re specifically materialist or physicalist naturalists (as almost all naturalists are), we must take it that conscious experience is wholly material or physical.Strawson goes on to describe how other naturalist philosophers have come to deny the reality of conscious experience:
And so we should, because it’s beyond reasonable doubt that [our mental] experience...is wholly a matter of neural goings-on: wholly natural and wholly physical.
But then—in the middle of the twentieth century—something extraordinary happens. Members of a small but influential group of analytic philosophers come to think that true naturalistic materialism rules out realism about consciousness. They duly conclude that consciousness doesn’t exist.Strawson and I agree, then, that qualia, and thus conscious experience, are real, but we disagree over his rejection of the claim that conscious experience cannot be completely reduced to material stuff. It seems to me that qualia are fundamentally different from matter, and it's exceptionally difficult to see how the experience of red, for instance, can be reduced to electrochemical phenomena in the brain.
They reach this conclusion in spite of the fact that conscious experience is a wholly natural phenomenon, whose existence is more certain than any other natural phenomenon, and with which we’re directly acquainted, at least in certain fundamental respects.
These philosophers thus endorse the Denial.
The problem is not that they take naturalism to entail materialism—they’re right to do so. The problem is that they endorse the claim that conscious experience can’t possibly be wholly physical. They think they know this, although genuine naturalism doesn’t warrant it in any way.
So they...claim that consciousness doesn’t exist, although many of them conceal this by using the word “consciousness” in a way that omits the central feature of consciousness—the qualia [i.e. our sensations of color, taste, fragrance, sound, pain, etc.]
As the late philosopher Jerry Fodor once said:
Nobody has the slightest idea how anything material could be conscious. Nobody even knows what it would be like to have the slightest idea about how anything material could be conscious. So much for the philosophy of consciousness.When we experience the sensation of color, or sweetness, or pain the immediate cause of that sensation is physical or material, but the sensation itself is not. A miniature scientist walking around inside someone's brain while the host is tasting sugar will only observe electrochemical reactions occuring in the neurons and synapses.
She'd see electrons whizzing about, chemicals interacting, and nerve fibers lighting up, perhaps, but however deeply she probed into the host's brain she wouldn't observe "sweetness" anywhere. Likewise, mutatis mutandis, with every other sensation her host might be experiencing.
So, I'd suggest a reformulation of the first syllogism:
- Naturalism entails materialism which entails that all reality is reducible to matter.
- Conscious experience probably cannot be reduced to matter.
- Therefore, Naturalism is probably false.
If, though, it's reasonable to think that the second premise is true, and a lot of philosophers, many metaphysical Naturalists among them, are convinced it is, then it's reasonable to believe the conclusion that Naturalism is probably false is true as well.