Very sure. The biological view just seems to be a tacked on requirement to reject emulations by definition. Anyone who would hold the biological view should answer the questions in this though experiment.
A new technology is created to extend the life of the human brain. If any brain cell dies it is immediately replaced with a cybernetic replacement. This cybernetic replacement fully emulates all interactions that it can have with any neighboring cells including any changes in those interactions based on inputs received and time passed, but is not biological. Over time the subject's whole brain is replaced, cell by cell. Consider the resulting brain. Either it perfectly emulates a human mind or it doesn't. If it doesn't, then what is there to the human mind besides the interactions of brain cells? Either it is conscious or it isn't. If it isn't then how was consciousness lost and at what point in the process?
Very sure. The biological view just seems to be a tacked on requirement to reject emulations by definition.
Note that I specifically said in the OP that I'm not much concerned about the biological view being right, but about some third possibility nobody's thought about yet.
...Anyone who would hold the biological view should answer the questions in this though experiment.
A new technology is created to extend the life of the human brain. If any brain cell dies it is immediately replaced with a cybernetic replacement. This cybernetic replacement fully emula
- 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?