SEX, DRUGS & MAGICK: A Journey Beyond Limits by Robert Anton Wilson
"Sex has many facets - biological sociological, esthetic, psychological, compulsive, ecstatic, tragic, playful, loving, perplexing and (I am told), even on occasion boring - but in this text is considered chiefly in its "transcendental" aspect. By this, I mean simply that in orgasm everybody experiences, to some degree, an explosion/implosion of the normal ego and a melting, merging, "oceanic" sensation of at-one-ment.
There are many types of drugs in the world - antibiotics; anesthetics; analgesics; narcotics; hypnotics; psychedelics; uppers and downers; dreamers and screamers - but here I am concerned with drugs that act centrally upon the higher nervous system and alter ego-definitions and perceived reality-tunnels. That is, drugs that produce "transcendental" or transpersonal states.
It is obvious that sex and drugs together can lead to more extraordinary and paranormal trans-ego experiences than either sex or drugs alone. This is an ancient Tantric "secret" and the present book was, as far as I know, the first ever published in America to discuss it explicitly, without using alchemical or other codes to obscure what was actually being said..."
- from the author's 1987 Preface to Sex, Drugs & Magick