1939-1945 1961-1975 20thcentury biography colby counterculture experimental hallucinogenicdrugs hallucinogenicdrugsandreligiousexperience hallucinogens harvarduniversity hispanicamericans history influencesamora intelligenceofficers julian leary metzner peursen psychologicalaspects psychologists psychology ralph ramdass rationalism research samora secretservice socialchange socialevolution sociallifeandcustoms studyandteaching timothy unitedstates vietnamwar williamegan worldwar