Thanks, I'll look into that book.
Currently, I'm investigating the so-called perennial, Gnostic philosophy of the ancient world that might inform Scholasticism or classical Christian theism. I suspect both the esoteric and exoteric theologies and creeds of the world's religions are so many garbled exploitations or obfuscations of the entheogenic experience (the peak states of consciousness caused especially by certain psychoactive drugs). But I'd rather speak of all of these dichotomies and progressions or regressions in more neutral, existentialist terms.