In my book review of David Hillman's The Chemical Muse, for altered-state
experiential phenomenology, I cited Benny Shanon's book Antipodes. I could
also mention "The Unfolding Self: Varieties of Transformative Experience" by
Ralph Metzner ( <http://www.amazon.com/o/ASIN/1579830005/>
http://www.amazon.com/o/ASIN/1579830005/ ). I categorize Metzner as a 20th
Century-only writer, not attuned to entheogen history, but he writes on Page
81 in his article "Molecular Mysticism", in the book "Gateway to Inner
Space: Sacred Plants Mysticism and Psychotherapy", Christian Ratsch (Ed.) (
<http://www.amazon.com/o/ASIN/1853270377>
http://www.amazon.com/o/ASIN/1853270377 ): "In my earlier writings, I
emphasized the newness of psychedelic drugs, the unimaginable potentials to
be realized by their constructive application; and I thought of them as
first products of a new technology oriented towards the human spirit. ...
my views [about their novelty] have changed under the influence of the
discoveries and writings of cultural anthropologists and ethnobotanists, who
have pointed to the role of mind-altering and visionary botanicals in
cultures across the world."

Thus the writers about psychedelics in the 1960s made a fatal strategic
misstep in treating psychedelics as new, modern, and unprecedented. Didn't
the 1960s know that "our own" religion was based on entheogens? No. Who
wrote the first book focusing on psychoactives in Western religion, in the
period of Late Antiquity? John Allegro did, not Wasson, who did his best to
suppress such a consideration about that era. As the first scholar to try
historical speculation about entheogens as the basis of a religion in Late
Antiquity, some of Allegro's bold postulates will remain standing, even
while his premise of an anti-drug Roman culture rested on the incorrect
status-quo assumption-framework and bolstered the existing, incorrect model
of drug attitudes in Late Antiquity.

Also, James Kent's book draft Psychedelic Information Theory (
http://www.tripzine.com/pit/ ) is surprisingly phenomenological for a
self-described hard-science approach. My first phase of research used the
cognitive phenomenology approach, but lately I'm focused on entheogen
history, explained by entheogen phenomena, rather than on entheogen
phenomena in isolation. So recently I've been on the lookout for
specifically entheogen *history* scholars, and tend to think of
contemporary-only entheogen researchers as uninformed, as continuing to make
the same mistake Metzner made in the 1960s. But really now, I'm calling for
an integration of present-focused entheogen theory together with
historically focused entheogen scholarship: both are needed, to inform and
complete the other. We need to combine the present-day phenomenological
perspective of James Kent, Benny Shanon, and Martin Ball with the historical
perspective of David Hillman, Clark Heinrich, and Carl Ruck.