Verificationism and the Zombie I
Now, back to our zombie. Poor bastard! He has no idea what chocolate really tastes like. He prefers Belgian and seems to savor it upon his palate, but he in fact has no consciousness of its wonderful flavor. As passionately as he behaves toward his wife, he loves her not. Writhing in pain from a wound, he is blessedly spared the agony you and I feel in such a case. You see, he has all the physical, behavioral and neural states we do, but none of the actual consciousness. He isn't biologically possible in our world, since the biology here requires that these states give rise to corresponding conscious states. But he is possible in a world that we may imagine. For there is no contradictions in the concept of "zombie," and therefore we can clearly and distinctly perceive the difference between consciousness, on the one hand, and physical and functional states, on the other.
Or so it is said. But there is nothing that would count as evidence that someone was a zombie. Suppose you parachute in to the possible world in which zombies are said to exist. Proceed then, in your imagination, to chat up the first cordial person you meet. Ask him a battery of questions and he opines on love, salvation, satire, overcoming depression. Prick him, and he cries out. He finds your chocolate delicious. And so forth. Meanwhile, have you any evidence that your spouse is not a zombie in counterexample to the biological laws I alluded to? None at all.
No, the concept of zombie has built into it the stipulation that zombies are undetectable: no physical or behavioral examination can discover them. Therefore, there is by definition nothing that would count as evidence that your specimen was a zombie.
If verificationism is correct, then "zombie" is not a meaningful term. And if "zombie" is not a meaningful term, then mind and the corresponding physical and functional states are not distinct.
Here you may tollens my ponens, as Aaron Haspel has when I broached this argument in the past. As I recall, he stated, "So much the worse for verificationism."
But you will have to bite the bullet here. If you don't accept principle V (stated in the two previous posts), then you countenance terms as meaningful which are devoid of evidentiary content and whose definitions may even stipulate that the terms can in principle never be any justification for applying them to any object. If you maintain that only an incoherent definition may be cause for dismissing a term as meaningless, you will have to explain why incoherence is a graver sin than the lack of evidentiary content. If a person proposes a noun or adjective X and we rifle through the infinity of possible evidentiary circumstances together with him, under each of which he declares that there is no evidence that X applies to any object, then we may consign his term X to the flames
Of course it is meaningless to speak of people who are not people. But it is equally meaningless to make reference to the distinctness of things for which there could never be evidence that they were separated from one another. To say that "consciousness and the physical and functional states that correspond to it are distinct even though nothing could ever count as evidence that the latter existed without the former" is meaningless talk.
The mental space that a meaning takes up may be quite large. Meanings of terms are sometimes large clusters of concepts. The corresponding evidential criteria for the application of a term may be an equally large cluster. The artificial substitution of one element of the cluster with a new component does not always make for an obvious contradiction. Sometimes the contradiction must be ferreted out. Also, the substitution can create vacuity of meaning in another way: by depriving the term of the possibility of justified application in any conceivable circumstance. And both contradictions and evidentiarily vacuous terms may be imagined to be applicable; such is the power of the imagination. When sleepy, I can imagine a world in which there is a round square or an absolutely undetectable gnome. So, the power of the mind to imagine the zombie is no evidence that mind is non-physical.
This is the first result of verificationism as I have proposed it. "Zombie" is a meaningless term. But if consciousness is distinct from the physical and functional states that correspond to it, then "zombie" is a meaningful term. So, consciousness is not distinct from the physical and functional states that correspond to it.