bug that causes it, so we will avoid dying from cancer by getting rid of particularly nasty chemicals in the environment. It is certainly; true that one cannot get tuberculosis without a tubercle bacillus, and the evidence is quite compelling that one cannot get the cancer mesothelioma without having ingested asbestos or related compounds. But that is not the same as saying that the cause of tuberculosis is the tubercle bacillus and the cause of mesothelioma is asbestos. What are the consequences for our health of thinking in this way? Suppose we note that tuberculosis was a disease extremely common in the sweatshops and miserable factories of the nineteenth century, whereas tuberculosis rates were much lower among country people and in the upper classes. Then we might be justified in claiming that the cause of tuberculosis is unregulated industrial capitalism, and if we did away with that system of social organization, we would not need to worry about the tubercle bacillus. When we look at the history of health and disease in modern Europe, that explanation makes at least as good sense as blaming the poor bacterium. What is the evidence for the benefits of modern scientific medicine? Certainly we live a great deal longer than our ancestors. In 1890, the years of life expected for a white child at birth in North America were only 45, whereas now the expected life span is 75 years, but that is not because modern medicine has prolonged the life of elderly and sick people. A very large fraction of the change in the average life expectancy is a tremendous reduction in infant mortality. Before the turn of the century and especially earlier in the nineteenth century, there was a considerable chance that a child never got to be a year old-in 1860, the infant mortality rate in the U. S. was 13 percent-, so the average life expectancy for the population as a whole was reduced considerably by this early death. The gravestones of people who died in the middle of the nineteenth century indicate a remarkable number of deaths at an old age. In fact, scientific medicine has done little to add years for people who have already reached their maturity. In the last 50 years, only about four months have been added to the expected life span of a person who is already 60 years old. As we all know, in modern Europe women live longer than men, but they used not to. Before the turn of the century, women died sooner than men did, and a common explanation offered by scientific medicine is that a leading