Tangle writes:
If there was such a thing as psychic ability we'd have known all about it long ago.
That kind of thing can't hide.
This seems a bit of a limited view.
If we're talking about somebody like Professor X existing in reality, then sure - the reality of his powers could easily be demonstrated experimentally if he chose to. We can safely conclude that people with psychic abilities on the order of X-Men characters do not exist in reality (or are very secretive).
Note that in the 1970s, various colleges started offering degree programs in parapsychology. I believe by the late 80s or early 90s, most of these programs were abandoned. The main issue is that none of them could verifiably demonstrate any evidence of any sort of tangible mechanism that confirmed things like ESP, telekinesis, clairvoyance, etc. I remember even reading about police departments hiring 'psychics' to assist in cold cases. And that never helped either.
Nowadays, there has been a small resurgence in things like 'noetics', which have tried to verify the existence of the soul or how thoughts might affect the physical world. From my knowledge, none of those things have provided any tangible evidence as well. At least, so far as I know.
For the most part, individuals claiming any sort of supernatural abilities and what not have been usually discredited quite easily by people like Randi and others. Houdini himself used to debunk claims of 'magic' and so forth because he was fully cognizant of the fact that everything he (and others did) were illusions.
From my perspective, looking at things this way is quite anachronistic. Because individuals often try to 'prove' the conclusion, which is backwards of how the scientific method functions. In the end, if anything is eventually discovered, it won't be supernatural. It will be natural. In the same way that someone isn't displaying any magical abilities when they touch a Van De Graaff generator and use it to send little shocks of electricity to objects or people.