Discusses the placebo concept and its purported concealment of a philosophical trap related to Cartesian dualism. The author points out that in discussing the placebo concept there is a temptation to say, in effect, that there is the body, which is a physiological system on which drugs and other medical treatments are supposed to operate, and there is the mind, which can be affected by suggestion to produce a spurious effect. Within this context, the author discusses the notion of pain; (...) on the materialist assumption it is illogical to make a distinction between "functional" and "real" pain. Al pain is real; only the mechanism by which it is produced differs. It is noted, however, that doctors often perceive the 2 types of pain differently. A similar difference in perception, the author believes, affects how they talk about the placebo phenomenon. It is often said in medicine that pharmacological effects are "real" whereas placebo effects are "merely psychological." Indeed, the author points out, the ghost has not yet been fully exorcised from the machine, despite the implicit assumption in medicine that materialism, rather than dualism, is true. (PsycINFO Database Record (c) 2010 APA, all rights reserved). (shrink)