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).
But this is not at all the sort of thing which people are usually talking about when they claim to believe in psychic abilities. They're talking about things like that implied by Prototypical's story - someone establishing some brief psychic connection with loved ones at the moment of their death, causing the loved one to think of them.
Now, I don't think that such abilities exist; but they are the kind of thing that would be extraordinarily difficult to demonstrate experimentally. How do you distinguish between a genuinely existing ability of this sort and mere coincidence?
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