Barry Arrington offers an interesting argument in Nature Wouldn’t Have Done It That Way:
In the zombie thought experiment we are supposed to imagine a person (let’s call him Fred) who looks and acts exactly like a fully conscious human being. Fred eats, drinks, converses, laughs, cries, etc. exactly like a human being, but he is in fact a biological robot with no subjective consciousness at all. …
This is, of course, a thought experiment.
Gelernter points out that from an outside observer’s perspective, a fully conscious, self-aware person cannot be distinguished from a zombie Fred. They behave exactly alike. Here is where it gets interesting. If a conscious person and a zombie behave exactly alike, consciousness does not confer a survival advantage on the conscious person. It follows that consciousness is invisible to natural selection, which selects for only those traits that provide a survival advantage. And from this it follows that consciousness cannot be accounted for as the product of natural selection. Nature would not have done it that way.
Where does this get us? It is hard to say. At the very least, it seems to me that the next time an anti-ID person employs the “God would not have done it that way” argument, I can respond with “And nature wouldn’t have either so where does that leave us?” response.
Commenter goodusername replies,
I’ve never seen anyone argue that consciousness was selected for (although such people may exist). Rather, it’s usually seen as a result or byproduct of other things that were selected for.
No one believes that every trait of every organism needs to be selected for in order to exist. Most features don’t exist as independent entities but, rather, are shaped by other parts of the organism. Many features exist at all only as a side effect of other features, such as the human chin.
I’m not sure if consciousness alone has any survival benefit, but it may exist as a side effect or byproduct of us being highly intelligent and highly social, and other mental traits.
I’m afraid this doesn’t get us anywhere.
If consciousness had survival value, we could conceivably have a naturalist discussion of why only humans have it. Given that it doesn’t have survival value, we are expected to see it as a side effect of “us being highly intelligent and highly social, and other mental traits.” But those traits are experienced as a product of consciousness (remember, zombie Fred doesn’t, so far as we know, exist, so he isn’t really an exception to this rule).
There is no reason— apart from a faith belief in naturalism—to believe that nature, which is unconscious, can produce human consciousness at all. Whether such consciousness has survival value or not. The best nature can do is produce animal consciousness (awareness of and response to one’s surroundings and experience). The rest of it—the abstractions, the ethical wrestles, the aesthetic quarrels, the tussle with mortality—does not seem to be part of nature’s remit. – O’Leary for News
PS: Added: It is not called the Hard Problem of Consciousness for nothing.