Advocates of alternative or complementary medicine frequently say things like, 'You need to treat the body, mind and spirit together', contending that mainstream medicine focuses too much on the purely physical. Alternative medicine prides itself on treating the person 'as a whole', taking account of their underlying psychological states as well as their physical symptoms. Suggest to an advocate of alternative medicine, however, that the effectiveness of such treatment may largely be due to the placebo effect (i.e. to the belief that the medicine will work rather than the medicine itself), and they will typically find this objectionable. Yet what is the placebo effect other than a perfect example of the mind and body working together, of the power of 'mind over matter'?