The Electric Kool Aid Acid Test - Tom Wolfe.

All about the group of people who first started the whole acid/hippy revolution in the sixties. They lived out on the edge - off their faces all the time. Then the "Leader", Ken Keesey, realized that it was all very well to go through the door in your mind that was opened by hallucinogens, but it was a bit pointless if you then closed it again and needed drugs to get back through. He reckoned you needed to "Go beyond drugs" so that you can permanently access open-minded states whenever you want without drugs.