To a generation in full revolt against any form of authority, Tune in, turn on, drop out became a mantra, and its populariser, Dr. Timothy Leary, a guru. A charismatic and brilliant psychologist, Leary became first intrigued and then obsessed by the effects of psychedelic drugs in the 1960s while teaching at Harvard, where he not only encouraged but instituted their experimental use among students and faculty. What began as research into human consciousness turned into a mission to alter consciousness itself. Leary transformed himself from serious social scientist into counterculture shaman, embodying the idealism and the hedonism of an age of revolutionary change. Timothy Leary is the first major biography of one of the most controversial figures in post war America.