An excellent book by author Jay Stevens relating the history of psychedelic use and abuse. The book takes us from Albert Hoffman's now famous bike ride to in depth examination of the horrible MKULTRA experiments by George Bush and the CIA. Jay's theorem, which is very rationally supported, is that all of the major breakthroughs in information technology and the increasing media presence is in large part due to the world's psychedelic explosion that began during the mid 60's. He relates the rites of many tribes throughout time that used psychedelic's as a rite of passage for teens into adulthood and also to benefit the tribes mental growth. He also relates LSD as one of the only successful treatments for alcoholism.
See also Terrance McKenna, Timothy Leary, Aldus Huxley and Cary Grant.