Fylobatica,
Thanks again for your reply. Although we don't agree, I enjoy discussing these issues.
The first point I want to address concerns you presumption that belief in afterlives, supernaturalism, or whatever is taken on because it is comforting. It is uncharitable to presume that this is always the case. For me, a potential afterlife is not comforting, insofar as it leaves open the possibility that the afterlife, or some people's afterlives, are bad, even hellish. I would take certain postmortem oblivion over some unknown probability of a horrible afterlife that could be inescapable. As I noted earlier, I was an atheist and anti-supernaturalist for most of my cognitively mature life, and found those beliefs comfortable. For the suicidal especially, the prospect of certain alleviation of pain through annihilation of consciousness upon death can be comforting, so the sword cuts both ways here. I reject atheism and anti-supernaturalism now because I have been compelled by evidence to believe that they are false.
The second point is your presumption that all materialist explanations must be fully ruled out before we can reject materialism and related metaphysical views. This is far too strong a standard, and basically begs the question against supernaturalism, since one can always simply insist that all apparent evidence of supernatural phenomena results from hallucinations, misperceptions, scientific errors, and so on. Since one can never rule such things out entirely, and indeed since all scientific theories (let alone metaphysical ones) are empirically underdetermined (see the Duhem-Quine thesis), this would leave us in a condition in which materialism could never be rejected. Furthermore, it can always be posited that there are further as yet undiscovered possible materialistic explanations of apparently supernatural phenomena -- materialists already do this when faced with phenomena that appear to contradict materialism. Once again, this falls into question-begging against supernaturalism.
Now on to your other claims:
"It's all about computation, just as shown by insects."
Once again, and as made clear in the very article you linked, there is no evidence whatsoever that insects have subjective experience. The notion that they do depends on the assumption that certain kinds of nervous structures are sufficient to generate subjective experience. Your points about the level of neural complexity needed to have full-blown human consciousness is beside the point. Again, we have nothing like evidence of subjective experience in anything other than humans, and even that evidence is only available because of the sophisticated communication that is possible between humans, but not between humans and non-human animals or among non-human animals. You argue again that everything will shake out in a way compatible with materialism in coming years; this is just an instance of assuming the truth of your position out of hand, and so isn't persuasive.
On NDEs, you're offering speculations about how various physical conditions could induce hallucinatory experiences in the nearly dead. These explanations have not gained much assent among NDE researchers precisely because they haven't been shown adequate to account for the full range of NDE phenomena -- their limitations are made clear in the article that I linked in my first post from Parnia (an expert on NDEs). More importantly, you are flatly ignoring the aspects of NDEs that seem impossible to accommodate in a materialistic framework: congenitally blind people (note that they have no vision to enhance) somehow acquiring veridical visual information, people recovering from brain death or near-brain death accurately reporting events that occurred while they were brain dead or nearly so (not events that occurred before or after, as all of these "what if NDEs occur before or shortly after brain death" explanations assume). Here is Parnia's summary statement regarding anomalous NDE phenomena that appear to support supernaturalist views: "Given that cardiopulmonary resuscitation (CPR) is insufficient to meet the metabolic requirements of the brain and that brain function ceases even with CPR, and is associated with a concurrent slowing and absence of cortical EEG within 2–20s, reports of consciousness during CPR—i.e. at a time when the brain is thought to be 'non-functional'—raise questions about the relationship between mind and brain/body".
"Actually psychosomatics has been scientifically proven."
The mere existence of psychosomatic healing phenomena isn't sufficient to explain all apparent medical miracles. No one has ever shown that psychosomatic phenomena can cause the regeneration of many centimeters of lost intestinal tissue, as has seemingly miraculously occurred (see the video I linked in my last post) -- that would fly in the face of all established medical science. There is a reason the authors of the review article regarding the Lourdes cures stated that these occurrences await "a scientific explanation," despite their manifest knowledge of psychosomatic healing processes. I should add that some of the Lourdes cures happened to people who were unconscious when they occurred -- this is clearly inconsistent with psychosomatic explanations that posit that religious rituals can engender psychosomatic healing processes.
I think that you should scrutinize your a priori assumptions favoring materialism more closely. What other theory gets a free pass every time it is faced with an observation that directly contradicts its predictions? To make my own position clearer, I don't think that the evidence we have clearly favors any particular religious, spiritual, or other supernatural doctrine. What I claim is that we have much data indicating that naturalism and atheism are probably false, and that some form of supernaturalism is true -- at minimum, received conceptions of naturalism would have to be profoundly reworked to accommodate the findings that I've mentioned, among others.
