Robert, as always you state very good points I've over looked.
>I think incrementally ala the Moravec suggestion of neuron by neuron
>functional replacement [inside-out replacement]. I do not see how this
>cannot work (given advanced technology) unless there is something very
>unusual (magical) about neurons we currently don't understand.
Nothing magical. Do you know how they grow, find, and connect with one another? Yes, wires are grown today, but can we make them to grow, find, and connect on their own? No doubt with advanced technology we can do this, but how advance and how far off are we? The properties of nerves are very different than the properties of wires we use today.
>Depends entirely on whether you are replacing it top-down (in which
>case we have to understand complex things first) or bottom-up
>(in which case we only have to understand much simpler things).
Actualy top down is easier with todays technology. All we have to do is know what it does and make something else that does the same thing.
Though, nanotechnology may not be that far off, complex applications of nanotechnology (such as biotechnology) is way in the future. After all, that is wat nanotechnology is. A different way of doing what nature has allready accomplished.