Aldous Huxley, author of Brave New World, The Doors of Perception and Island gave a frank interview in 1961 in which he talked about a number of philosophical topics, including his use of the hallucinogenic compound mescaline.
The recording was released as a double LP vinyl in 1973 and later in CD format in 2002. Titled Speaking Personally, the CD is a treasured item in my collection.