If I would make an argument in favor of mind uploading (or substrate independent minds) it would not be a logical deduction from what we know about neuroscience but from what we don’t know. As one of the leading philosophers of mind David J. Chalmers has argued in this insightful paper about the Singularity and mind uploading:
Can an upload be conscious? The issue here is complicated by the fact that our understanding of consciousness is so poor. No-one knows just why or how brain processes give rise to consciousness. Neuroscience is gradually discovering various neural correlates of consciousness, but this research program largely takes the existence of consciousness for granted. There is nothing even approaching an orthodox theory of why there is consciousness in the first place. Correspondingly, there is nothing even approaching an orthodox theory of what sorts of systems can be conscious and what systems cannot be….
It is true that we have no idea how a nonbiological system, such as a silicon computational system, could be conscious. But the fact is that we also have no idea how a biological system, such as a neural system, could be conscious. The gap is just as wide in both cases. And we do not know of any principled didifferences between biological and nonbiological systems that suggest that the former can be conscious and the latter cannot. In the absence of such principled didifferences, I think the default attitude should be that both biological and nonbiological systems can be conscious
One can argue with this derivation of what the “default position” should be, but his more skeptical approach has a degree of modesty in its favor that is often lacking in transhumanist circles.
David J. Chalmers also discusses cryonics in a favorable context:
Cryonic technology offers the possibility of preserving our brains in a low-temperature state shortly after death, until such time as the technology is available to reactivate the brain or perhaps to upload the information in it. Of course much information may be lost in death, and at the moment, we do not know whether cryonics preserves information sufficient to reactivate or reconstruct anything akin to a functional isomorph of the original. But one can at least hope that after an intelligence explosion, extraordinary technology might be possible here
On his blog he also writes that “for the last couple of weeks I have been in Oxford giving the John Locke Lectures on Constructing the World. The title is an homage to Rudolf Carnap’s 1928 book Der Logische Aufbau Der Welt. The lectures are based on a book I have been writing for the last couple of years, trying to execute a project that is reminiscent of Carnap’s in certain respects.”
A person who discusses mind uploading in a meaningful context, gives cryonics a fair hearing, and has a work in progress that is inspired by Rudolf Carnap’s The Logical Structure of the World should not be ignored, let alone be ridiculed.