That's only simple on a superficial level...
Agreed. It buries all the assumptions of supernatural causes and effects. To be sure, there is assumption in either attempt to explain clairvoyance. So the goal is not to explain the observations without assumption. It's to explain them with the fewest, most reasonable assumptions.
We know there exist techniques to simulate supernatural effects. We know that people use them to support the proposition that they have supernatural ability. Their motives for doing so vary in moral value from entertainment to fraud. Regardless, almost all those motives are frustrated by widespread publication of those techniques. Thus while some of the techniques are well known, we cannot suppose that all are. But it is not necessary to suppose that large numbers of people must be kept in the dark in order for the enterprise to succeed. It is necessary only that the intended subject not perceive the technique. Or, in the case of entertainment, that the intended subject have less interest in discovering the technique than in watching it operate.
In a different thread, Scorpion proposed that a similar framework could exist for the supernatural hypothesis. He proposed that the spiritual powers that be concealed their existence and influence to achieve a dharmic effect. But his argument was riddled with holes and inconsistencies. He couldn't make it work or demonstrate that any part of it was supported by evidence. At least here, the existence of a spiritual world qualifies as an extraordinary claim requiring extraordinary proof. You can't assume them into existence, cobble them together into a framework that vaguely resembles the prosaic explanation, and ask people to accept that this is simpler.
For any given anecdote, the obstacle is generally that no further evidence can be developed to test variants of the trickery-and-deception hypothesis. This is why skeptics want professed abilities to be demonstrated under controlled circumstances, and why the unscrupulous practitioners shun them. The question is then what is reasonable to believe in the absence of that opportunity. I contend it is perfectly reasonable to presume that the reported observations are more likely due to a trickery-or-deception technique, even if unknown, than to actual supernatural operation.
That presumption is requires some assumptions. First, the purpose of the natural techniques is to mimic what are supposed to be supernatural effect. We assume this effort succeeds in a reasonable number of cases.
Second, the proposed natural technique has to explain the observations. We don't circularly assume they do. Instead, we note that the skill of the illusionist depends in part on special knowledge of natural phenomena, human capacity and nature, etc. Further, we see countless examples of stage magic that prove the ability of this knowledge to create observations that defy superficial hypotheses. Thus we assume that our impression that the observations exceed most proffered hypotheses does not preclude us from a reasonable presumption.
Third, the proposed technique has to defy falsification by the present evidence. We accept this as the central principle of stage magic. We accept it as the inevitable limitation of anecdotal happenstance. But we note further that deception -- innocent or otherwise -- presumes intent and effort to conceal evidence. Thus we assume, as above, that the paucity of evidence with which to falsify hypotheses does not preclude holding the presumption as reasonable.
In any case, it's fundamentally unreasonable for the null hypothesis to require antecedents whose existence has no evidentiary support. The null hypothesis should be the one whose proposed causes and effects are evidenced, if not outright factual.
