FEELING, FUNCTING, AND ALAN TURING

DA: "'like a stone' would not... satisfy David Chalmers. The zombie is supposed to carry on in a normal human way... but to be lacking consciousness.  It is hard to imagine a stone carrying on in any way at all."

What we are talking about is the presence or absence of the capacity to feel. A stone cannot feel. There's lots of other things that are true of a stone too: A stone can't do anything either (except fall when dropped, or just lay there wherever it is). But the relevant thing is that it doesn't feel

Now I have no idea whether or not there can be zombies (and David Chalmers has no idea either).

But I can give you one important example of what a zombie would be, if there could be zombies: A robot that can pass the Turing Test: act and talk in the world, indistinguishably (in what it does) from any of us, for a lifetime -- but without feeling anything at all whilst doing it all (just like a stone).

The reason this example is particularly instructive is that it brings out the fact that although lifelong performance capacity that is Turing-Indistinguishable from our own is certainly no guarantor of consciousness (feeling), it is the best we can hope for, and the closest we can ever hope to an explanation of feeling (which is not very close: it just explains the functing with which feeling is apparently correlated). The rest is down to whether or not there can be Turing-scale performance capacity (functing) without feeling. (I think there cannot be, but I certainly cannot prove it; I can't even explain how or why, because no one can explain how or why any function is a felt function, even though felt functions clearly exist -- in us, and other organisms.)

DA: "Does a worm '"feel"?  Probably yes... though in a sense almost certainly incomprehensible to us. Is a worm "conscious" then?  If not why not? etc, etc"  

Probably yes, a worm can feel (no scare-quotes needed), which means exactly the same thing as that the worm is conscious. 

(We can't be sure about anyone/anything else either, because of the other-minds problem, but a worm is almost as good a bet as another person.)

Whether or not the worm feels what I feel, whether or not I can understand what it feels like to be a worm, and indeed what and how much a worm feels is all completely irrelevant. The only thing that matters is whether the worm feels anything at all. If it does, it's conscious (because that's what it means to be conscious), and the fact that it feels is as utterly inexplicable as the fact that I feel.

DA: "consciousness... is so seldom - if ever - carefully defined.  There is an apparent assumption that we "just know" what we mean by it." 

Consciousness does not need to be "defined": it just needs to be pointed to. (That's sometimes called an "ostensive definition".) Something is conscious if it feels. And "feels" does not need to be defined either. Anyone who can speak already understands what it means to feel (with the possible exception of the Turing-Indistinguishable robot, if there can be zombies!). The meaning of our elementary words -- see, hear, touch, smell, taste -- are all grounded in our shared sensorimotor capacity to feel.

DA: "talk about zombies as beings minus consciousness seems so futile... Minus what exactly?"  

Minus feeling (like a stone, if, that is, there can be zombies -- i.e., entities that have our doing capacities but without feeling -- at all).

SH