And to give them the situation to dramatize, we have the two villains of the piece, immensely powerful, immensely unconcerned with mere mortals, and having a history of being prone to philosophical experimentation -- metaphysics, epistemology, ethics. Which is why the characters in the story immediately (and correctly) guess that they are behind the current pickle. Which means that they need to have such experiments in their past.
And above and beyond that, said experiments have to be high-handed and discernible by their subjects. And yet such that they can be briefly recounted so that the story can move briskly on -- it's not a tale of sitting about and telling tales of the old days and the great battles then -- with adequate knowledge of how nasty they can be. Non-lethal.
They can have a hallucinogenicly precise dream of real life, a la Descartes, and I think I can let loose qualia so that people will actually experience what other people experience. Or perhaps properties set loose from any actual object -- redness, quickness, hotness.
Once I actually started writing the scenes where the characters toss the notions about, I wasn't entirely happy with them. sigh. And they're just a bit of background info I have to devise. . . .
Perhaps I'll throw in an Unmoved Mover, or at least a model of one.