"But I have wondered if there might not be colleges and faculties of other experiences than yours, and whether even now, in the far corners of other continents, powers not yours are being brought to fruition." Charles Williams, Shadows of Ecstasy
The more I think about it, the more I am convinced that those three guys are right.
In Terry Pratchett's A Hat Full of Sky, a witch's cabin is inhabited by a invisible creature the witch calls Oswald. At least, she thinks it is. Whenever she puts a fork in amongst the spoons, the drawer rattles, pops open, and the fork leaps over into the correct spot. If something gets dropped, a dustpan and brush appear and magically sweep things up. If Miss Level (the witch) mixes some salt together with the pepper, Oswald will happily (so she surmises) spend an afternoon sorting the salt grains from among the pepper.
Given the phenomenon Pratchett describes, it's hard to think of any hypothesis that would cover it, other than that of an invisible, intelligent agent. If we had numerous instances, well documented, of such occurrences, we would have to conclude that incorporeal intelligent beings exist.
But we don't.
In Williams's story, there is an uprising of Africans who wield powers not understood by European science. They are able to prolong life far beyond the normal human lifespan. They can exert a sort of mind control on others.
In Williams's day, it might have still seemed possible that some remote group in Africa had developed an alternate "technology," one based in supernatural rather than natural causes. Today, having made contact with numerous such remote groups all over the world, and having discovered no technologies that make effective use of supernatural forces, it's hard to believe that such skills exist anywhere.
It's not that "colleges and faculties of other experiences" don't exist: nearly all human groups make attempts to manipulate the supernatural forces of their systems of belief. It's just that they don't work: appealing to the supernatural is not an effective way of getting things done.