For Aldous Huxley it was the next step in human evolution; for the CIA it was a potential tool for mind control; for Timothy Leary it was the liberator of humankind (a belief that led to his being branded "the most dangerous man in America"); for Ken Kesey and his Merry Pranksters it fueled the notorious Acid Tests; and it was the improbable common denominator that united such disparate figures as Allen Ginsberg, Cary Grant, G. Gordon Liddy, and...