• We can study various psychic functions and also the more primitive sensory functions, such as seeing, hearing, and so on, which constitute our image of our everyday world. They have a material side and the psychic side. And that is a gap which you cannot explain.

    Albert Hofmann: We can study various psychic functions and also the more primitive sensory functions, such as seeing, hearing, and so on, which constitute our image of our everyday world. They have a material side and the psychic side. And that is a gap which you cannot explain.
    "Stanislav Grof interviews Dr. Albert Hofmann Esalen Institute, Big Sur, California". Interview with Stanislav Grof, www.maps.org. 1984.