This is also a great quote from that 1999 NY Times article on placebos in medicine:

The truth is that the placebo effect is huge — anywhere between 35 and 75 percent of patients benefit from taking a dummy pill in studies of new drugs — so huge, in fact, that it should probably be put to conscious use in clinical practice, even if we do not entirely understand how it works. For centuries, Western medicine consisted of almost nothing but the placebo effect. The patient who got better after a bleeding — or a dose of fox lung, wood lice, tartar emetic or any of the other charming staples of the 19th-century pharmacopoeia — got better either in spite of them or because of their symbolic value. Such patients believed in the cure and in the authority of the bewigged gentlemen administering it, and the belief gave them hope and the hope helped make them well. There were exceptions — remedies, like quinine for malaria, the vaccine for smallpox and morphine for pain relief, that actually worked. But generally speaking, if all the drugs of the day “could be sunk to the bottom of the sea,” as Oliver Wendell Holmes observed in 1860, “it would be all the better for mankind — and all the worse for the fishes.”

And:

In fact, medical science has improved so much and so fast in the last 40 years that it is easy, perhaps, for doctors to neglect the part of medicine that is not science at all. The ready and lavish display of sympathy, the laying on of hands, the projection of a slightly mystical authority — these are now more often the province of alternative medical practitioners, who have no compunction about manipulating them.