Project MKUltra, also called the CIA mind control program, is the code name given to a program of experiments on human subjects that were designed and undertaken by the United States Central Intelligence Agency—and which were, at times, illegal.
Of course, the drug dose does not produce the transcendent experience. It merely acts as a chemical key — it opens the mind, frees the nervous system of its ordinary patterns and structures. The nature of the experience depends almost entirely on set and setting. Set denotes the preparation of the individual, including his personality structure and his mood at the time. Setting is physical — the weather, the room’s atmosphere; social — feelings of persons present towards one another; and cultural — prevailing views as to what is real. It is for this reason that manuals or guide-books are necessary. Their purpose is to enable a person to understand the new realities of the expanded consciousness, to serve as road maps for new interior territories which modern science has made accessible.
—Timothy Leary, Ralph Metzner, Richard Alpert
Timothy Leary, Ralph Metzner, Richard Alpert, The Psychedelic Experience: A Manual Based on the Tibetan Book of the Dead, Kensington Publishing Corp., 1964/1992. pp. 11