I find it helps to break down the category of 'consciousness.' What is it that one is saying when one says that "Consciousness is essentially biological"? Here it's important to be careful: there are philosophers who gerrymander categories. We can start by pointing to human beings, as we take human beings to be conscious, but obviously we aren't pointing at every human attribute. (For instance, having 23 base pairs of chromosomes isn't a characteristic we are pointing at.) We have to be careful that when we point at an attribute, that we are actually trying to solve the problem and not just obscure it: if I tell you that Consciousness is only explainable by Woogles, that's just unhelpful. The term we use needs to break down into something that allows us to (at least in principle) tell whether or not a given thing is conscious. If it can't do THAT, we are better off using our own biased heuristics and forgoing defintions: at least in the former case, I can tell you that my neighbor is conscious and a rock isn't. Without some way of actually telling what is conscious and what is not, we have no basis to actually say when we've found a conscious thing.
It seems like with consciousness, we are primarily interested in something like "has the capacity to be aware of its own existence." Now, this probably needs to be further explicated. "Awareness" here is probably a trouble word. What do I mean when I say that it is "aware"? Well, it seems like I mean some combination of being able to percieve a given phenomenon and being able to distinguish both degrees of the phenomenon when present and distinguishing the phenomenon from other phenomenon. When I say that my sight makes me aware of light, I mean that it allows me to both distinguish different sorts of light and light from non-light: I don't mistake my sight for hearing, after all. So if I am "aware of my own existence" then I have the capacity to distinguish my existence from things that are not my existence, and the ability to think about degrees to which I exist. (in this case, my intuition says that this caches out in questions like "how much can I change and still be me?")
Now, there isn't anything about this that looks like it is biological. I suppose if we came at it another way and said that to be conscious is to "have neural activity" or something, it would be inherently biological since that's a biological system. But while having neural activity may be necessary for consciousness in humans, it doesn't quite feel like that's what we are talking about when we talk about what we are pointing to when we say "conscious." If somehow I met a human being and was shown a brain scan showing that there was no neural activity, but it was apparently aware of itself and was able to talk about how its changed over time and such and I was convinced I wasn't being fooled, I would call that conscious. Similarly, if I was shown a human being with neural activity but which didn't seem capable of distinguishing itself from other objects or able to consider how it might change, I would say that human being was not conscious.
You've chosen one of the easier aspects of cosnciousness: self-awareness rather than, eg. qualia.
The "necessarily biological" could be aposteriori nomic necessity, not apriori concpetual necessity, which is the only kind you knock down in your comment.
- Eliezer Yudkowsky, "Value is Fragile"
I had meant to try to write a long post for LessWrong on consciousness, but I'm getting stuck on it, partly because I'm not sure how well I know my audience here. So instead, I'm writing a short post, with my main purpose being just to informally poll the LessWrong community on one question: how sure are you that whole brain emulations would be conscious?
There's actually a fair amount of philosophical literature about issues in this vicinity; David Chalmers' paper "The Singularity: A Philosophical Analysis" has a good introduction to the debate in section 9, including some relevant terminology:
So, on the functionalist view, emulations would be conscious, while on the biological view, they would not be.
Personally, I think there are good arguments for the functionalist view, and the biological view seems problematic: "biological" is a fuzzy, high-level category that doesn't seem like it could be of any fundamental importance. So probably emulations will be conscious--but I'm not too sure of that. Consciousness confuses me a great deal, and seems to confuse other people a great deal, and because of that I'd caution against being too sure of much of anything about consciousness. I'm worried not so much that the biological view will turn out to be right, but that the truth might be some third option no one has thought of, which might or might not entail emulations are conscious.
Uncertainty about whether emulations would be conscious is potentially of great practical concern. I don't think it's much of an argument against uploading-as-life-extension; better to probably survive as an up than do nothing and die for sure. But it's worrisome if you think about the possibility, say, of an intended-to-be-Friendly AI deciding we'd all be better off if we were forcibly uploaded (or persuaded, using its superhuman intelligence, to "voluntarily" upload...) Uncertainty about whether emulations would be conscious also makes Robin Hanson's "em revolution" scenario less appealing.
For a long time, I've vaguely hoped that advances in neuroscience and cognitive science would lead to unraveling the problem of consciousness. Perhaps working on creating the first emulations would do the trick. But this is only a vague hope, I have no clear idea of how that could possibly happen. Another hope would be that if we can get all the other problems in Friendly AI right, we'll be able to trust the AI to solve consciousness for us. But with our present understanding of consciousness, can we really be sure that would be the case?
That leads me to my second question for the LessWrong community: is there anything we can do now to to get clearer on consciousness? Any way to hack away at the edges?