Woj expresses everything with great certainty.
[WS:] This was a tongue in cheek piece against culturalism and idealism, not a scientific account - an attempt to explain idealism itself in crude materialistic terms. Sort of like Freudians "analyzing" their critics and proposing that their rejection of psychoanalysis results from their repressed feelings toward sex and thus confirms psychoanalysis.
If I were to write a more scientifically oriented piece, I would focus on the latest work of neuro-science linking emotions and states of mind to the functioning - and malfunctioning - of the brain. I would also add that this research, while promising, is still in its infancy. However, I would not venture into ex-post facto explanations that any particular behavioral trait reflects evolutionary advantage, because that would smack of teleology. (PS. It would not be teleology only if we established a connection between a particular trait and a chance of survival from actual observations and then posited that a similar connection must have existed in the past).
Jks: I do rather suspect that evolutionarily speaking, the advantage of delusion is limited; for example, in providing religious solace, and that for much of human and pre-human evolution the greater advantage was in the ability to find out the truth, so as not to, e.g., walk into walls, fall off cliffs, find food, keep the kids from being eaten, etc. But this is speculative, of course. Nietzsche's questions are still good ones.
[WS:] Of course it is speculative, because one can equally forcefully argue that delusional tendencies are maladaptive as they reduce the capacity of food acquisition and danger evasion, and hence the chance of survival. These two hypotheses can be decided only by empirical tests, which requires actual observations.
Furthermore, to play devil's advocate I'd to conjecture that there is a lot of "slack" in nature (just as there is a lot of slack in organizations), which makes ex-post facto linking of current behavioral traits highly questionable, to say the least. This means two things. First, certain traits that appear as a result of genetic mutations are neither beneficial nor detrimental for survival. Second, traits that are detrimental may be counter-balanced by beneficial traits, and thus have negligible effect on the chance of survival (especially of complex organisms).
In both cases, the "slack" in chances of survival allows evolutionary preservation of traits that are either neutral or even detrimental. Because of that slack, it is fallacious to argue that all current traits reflect past evolutionary advantages - as it is quite possible that at least some, if not most, of such traits might have been unaffected by natural selection at all.
Wojtek