“I don’t think you could discover consciousness if you didn’t perturb it, because as Marshall McLuhan said, whoever discovered water, it certainly wasn’t a fish. Well, we are fish, swimming in consciousness. And yet we know it is there. The reason we know it is there is because if you perturb it, then you see it. And you perturb it by perturbing the engine that generates it, which is the mind-brain system resting behind your eyebrows. If you swap out the ordinary chemicals that are running that system in an invisible fashion, then you see: it’s like dropping ink into a bowl of clear water, suddenly the convection currents operating in the clear water become visible, because you see the particles of ink tracing out the previously invisible dynamics of the standing water. The mind is precisely like that, and the psychedelic is like a dye-marker being dropped into this aqueous system.”
—Terence McKenna, The Importance of Psychedelics