Thought experiments as knowledge
One of the most remarkable aspects about the ongoing debates concerning the technical feasibility of mind uploading is the excessive confidence that some people have that these issues can be resolved without further experimental validation. The (implicit) assumption seems to be that our current understanding of the neuroscience of consciousness is sufficient to demonstrate the technical feasibility of mind uploading by logical deduction from these findings alone. This is a mysterious claim for at least two reasons. The most fundamental reason is that the scientific study of consciousness has not nearly evolved to a stage that allows for making bold claims about the subject, let alone its far-reaching consequences. The other reason is that, in the absence of empirical examples of substrate-independent life in general, it cannot be argued that such logical arguments are just innocent or inescapable conclusions from what we already do know.
It should not be surprising that such arguments fail to convince some of the participants in the debate. After all, many “mind uploaders” also believe that the case for cryonics is just a straightforward exercise of Pascal’s Wager and the technical feasibility of molecular nanotechnology can be settled by arguing that the idea does not “contradict the laws of physics.” As I have argued in a more detailed article about this tendency, the common denominator in all of this is the excessive role that is assigned to logical arguments (or rationalism). But there is an important difference between, let’s say, predicting the unmeasured viscosity of a specific aqueous solution from a formula that has been derived from numerous measurements on the one hand and drawing far-reaching conclusions from general scientific observations or even philosophical premises (materialism, reductionism) on the other hand. This does not mean that one should completely refrain from speculation about future technologies, but it should induce a habit of having less confidence in your conclusions as the chain of assumptions and logical arguments lengthens, let alone if your conclusions are highly controversial.
One could object that since advocates of mind uploading are generally strong advocates of cryonics, that even treating their arguments with skepticism risks alienating prospective supporters of cryonics. The fact of the matter is, however, that presenting cryonics as just one element in a larger futurist framework strongly weakens the point that cryonics is an experimental medical procedure, not an ideology or life-style. It is not possible to present cryonics in a fashion that does not alienate anyone at all. But presenting cryonics as an experimental medical procedure without additional ideological, philosophical, or sociological add-ons has the important merit of reducing this amount of alienation to the greatest possible degree. It also has the distinct advantage that it facilitates the recruitment of people who can move the field forward; experimental scientists and medical professionals.