It seems worth mentioning that ecstasy derives from a term in ancient Greek meaning to stand "out of the body" (or mind.) This was similar to the idea of being "beside oneself" with joy, for example, but carried a more exact, literal sense, reminiscent of the descriptions given by some psychedelic veterans or religious practitioners, or by some of the people who have undergone "out of body experiences" in near-death situations.

The term was used to describe the trance experience of practitioners of the various Greek mystery religions, such as Orphism, and there were shamanic doctors, called Ecstatici who were thought to heal others during their trances.

Plotinus, a practitioner of Orphism and a contemporary of Pythagoras, though not himself a Pythagorean, gives the following description: (Enneads, IV.8. I)

Many times it has happened: Lifted out of the body into myself; becoming external to all other things and self-encentred; beholding a marvellous beauty; then, more than ever, assured of community with the loftiest order; [...] poised above whatever in the Intellectual is less than the Supreme: yet, there comes the moment of descent from intellection to reasoning, and after that sojourn in the divine, I ask myself [...] how did the soul ever enter into my body, the soul which even within the body, is the high thing it has shown itself to be.

The Plotinus quote is from Bertrand Russell's A History of Western Philosophy, where, amusingly enough, the translation is attributed to 'McKenna'.