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 McKennaOne has attained a very fortunate incarnation, I think, to be in a culture, in a place, in a time when psychedelic knowledge is available.
Terence McKennaIt's as though a certain level of intoxication with the mushroom is the precondition for being able to communicate, but is not itself enough.
Terence McKenna