Authors:

We can study material processes and various processes at the energetic level, that is what we can do as natural scientists. And then there comes something quite different, the psychic experience, which remains a mystery.

"Stanislav Grof interviews Dr. Albert Hofmann Esalen Institute, Big Sur, California". Interview with Stanislav Grof, www.maps.org. 1984.
We can study material processes and various processes at the energetic level, that is what we can do as natural scientists. And then there comes something quite different, the psychic experience, which remains a mystery.