Leary later explained in his 1983 autobiography Flashbacks: "'Turn on' meant go within to activate your neural and genetic equipment. Become sensitive to the many and various levels of consciousness and the specific triggers that engage them. Drugs were one way to accomplish this end. 'Tune in' meant interact harmoniously with the world around you - externalize, materialize, express your new internal perspectives. Drop out suggested an elective, selective, graceful process of detachment from involuntary or unconscious commitments. 'Drop Out' meant self-reliance, a discovery of one's singularity, a commitment to mobility, choice, and change. Unhappily my explanations of this sequence of personal development were often misinterpreted to mean 'Get stoned and abandon all constructive activity.'"
We are dealing with the best-educated generation in history. But they've got a brain dressed up with nowhere to go. Science is all metaphor. In the information age, you don't teach philosophy as they did after feudalism. You perform it. If Aristotle were alive today he'd have a talk show. If you don't like what you are doing, you can always pick up your needle and move to another groove. If you take the game of life seriously, if you take your nervous system seriously, if you take your sense organs seriously, if you take the energy process seriously, you must turn on, tune in, and drop out.
At one point consciousness-altering devices like the microscope and telescope were criminalized for exactly the same reasons that psychedelic plants were banned in later years. They allow us to peer into bits and zones of Chaos.