set and setting: The inner and outer environments in which a drug experience takes place; “set”
is a term for the mind-set and expectations the person brings to the experience, and “setting” is
the outward circumstances in which it takes place. Set and setting are particularly influential in
the case of psychedelics. The terms are usually credited to Timothy Leary, but the concept was
recognized and made use of by earlier researchers such as Al Hubbard.
tryptamine: A class of organic molecule common in nature, and the name for one of the two
principal types of psychedelic compounds; the other is the phenethylamines. LSD, psilocybin, and
DMT are tryptamines. The neurotransmitter serotonin is also a tryptamine.