"Deliberate provocation of mystical experience, particularly by LSD and related hallucinogens, in contrast to spontaneous visionary experiences, entails dangers that must not be underestimated. Practitioners must take into account the peculiar effects of these substances, namely their ability to influence our consciousness, the innermost essence of our being. The history of LSD to date amply demonstrates the catastrophic consequences that can ensue when its profound effect is misjudged and the substance is mistaken for a pleasure drug. Special internal and external advance preparations are required; with them, an LSD experiment can become a meaningful experience. Wrong and inappropriate use has caused LSD to become my problem child."

“I know LSD; I don't need to take it anymore. Maybe when I die, like Aldous Huxley.”

“In studying the literature connected with my work, I became aware of the great universal significance of visionary experience. It plays a dominant role, not only in mysticism and the history of religion, but also in the creative process in art, literature, and science. More recent investigations have shown that many persons also have visionary experiences in daily life, though most of us fail to recognize their meaning and value. Mystical experiences, like those that marked my childhood, are apparently far from rare.”

“LSD wanted to tell me something. … It gave me an inner joy, an open mindedness, a gratefulness, open eyes and an internal sensitivity for the miracles of creation.”

“I was visited by Timothy Leary when he was living in Switzerland many years ago. He was a very intelligent man, and quite charming. I enjoyed our conversations very much. However, he also had a need for too much attention. He enjoyed being provocative, and that shifted the focus from what should have been the essential issue. It is unfortunate, but for many years these drugs became taboo. Hopefully, these same problems from the Sixties will not be repeated.”

“Outside is pure energy and colorless substance. All of the rest happens through the mechanism of our senses. Our eyes see just a small fraction of the light in the world. It is a trick to make a colored world, which does not exist outside of human beings.”

“I believe that shortly after LSD was discovered, it was recognized as being of great value to psychoanalysis and psychiatry. It was not considered to be an escape. It was a very important discovery at that time, and for fifteen years it could be used legally in psychiatric treatment and for scientific study in humans. During this time, Delysid, the name I gave to LSD, was used safely, and was the subject of thousands of publications in the professional literature. Actually, just last week, I had visitors from the Albert Hofmann Foundation, to whom I gave all of the original documentation, which had been stored at the Sandoz Laboratories. This early work was very well documented, and shows how well research with LSD went until it became part of the drug scene in the 1960s. So, from originally being part of the therapeutic pharmacopeia, LSD became a drug of the street and inevitably it was made illegal. Because of this reputation, it became unavailable to the medical field, and so the research, which had been very open, was stopped. Now it appears that this research may start again. The importance of such investigations appears to be recognized by the health authorities, and so it is my hope that finally the prohibition is coming to an end, and the medical field can return to the explorations which were forced to stop thirty years ago.”