Certainly neo-Platonism, Plotinus and Porphyry and that school are psychedelic philosophers. Their idea of an ascending hierarchy of more and more rarefied states is a sophisticated presentation of the shamanic cosmology, which is the cosmology that one experientially discovers when they involve themselves with psychedelics.
Terence McKennaNobody is smarter than you are. And what if they are? What good is their understanding doing you?
Terence McKennaThe world which we perceive is a tiny fraction of the world which we can perceive, which is a tiny fraction of the perceivable world.
Terence McKennaI'm proposing on one level that hallucinogens be thought of as almost as social pheromones that regulate the rate at which language develops, and therefore regulate human culture generally.
Terence McKenna