We are proud of humanity's progress in medicine. We like our doctors; they are consistently among the professions that the public trusts the most. There are countless books on histories of medicine, citing a proud tradition from Hippocrates on down to the latest in gene therapy. Doctors gradually but eagerly advanced to take in new techniques and new science to get us where we are today. Except this did not happen. "For 2,400 years patients have believed that doctors were doing them good; for 2,300 years they were wrong." The unsparingly pessimistic view of the overwhelming failures of doctors is that of David Wootton, a professor of history who has written _Bad Medicine: Doctors Doing Harm Since Hippocrates_ (Oxford University Press). The world has adopted the scientific method as the way of getting information and using it, but before the dawn of germ theory, there was only a firm hold on medical traditions, and the traditions were wrong. Even worse, in many cases medical treatment became more dangerous over time, as in the case of nineteenth century hospitals causing the deaths of mothers in childbirth far more effectively than independent midwives could do. This is a grim story, and if we are past the centuries of medicine-as-tradition, there are still reasons to think that doctors may be addicted to doing the things they do because that's what they have always done.
For a couple of thousand years, medicine was based on Hippocrates and his successors, especially Galen, whose theories dealt with balancing bodily fluids, and to help nature along, doctors would induce vomiting or diarrhea, apply hot irons to the body, or drain off some blood. There was no physiological benefit in such treatments, which could do nothing but make things worse. Yet such treatments were the staple of medical practice until the middle of the nineteenth century. One reason is that people generally tend to be healthy, and when they are sick they generally tend to get well; bodies are designed to do this and do it fairly well, even without help (or hindrance) from medical treatment. Another reason is the placebo effect, which only got to be understood in the nineteenth century. A final and overwhelming reason for doctors' failure to move out of the tradition of treating humors was that having satisfied themselves that such treatment worked, and having formed a pattern of using it and taking fees for using it, they were much more interested, over many centuries, to preserve and transmit the tradition rather than to question or try to improve it. This was despite new understanding of, say, blood circulation, or the worlds of beasties revealed by the microscope.
Wootton's history is one of lost chances; medical science, he shows over and over, could have taken advantage of concepts known in biological science centuries beforehand, but did not do so. Doctors were, like any other group of people, set in their ways. They thought they had as good therapies as could be gotten, and so psychological and cultural factors kept medicine from advancing. It was not that there were gaps in equipment or pure science or intellectual resources, but bad arguments repeatedly drove out good and kept the status quo. It happened for centuries, and might happen in other ways in the future; a bit of skepticism on the parts of both doctors and patients could prove healthful.