But while modern science can boast of so many startling achievements in the health fields, its role has not been so unique and its effectiveness not so complete as is commonly claimed. In reality … the monstrous spector of infection had become but an enfeebled shadow of its former self by the time serums, vaccines, and drugs became available to combate microbes. Indeed, many of the most terrifying microbial diseases — leprosy, plague, typhus, and the sweating sickness, for example — had all but disappeared from Europe long before the advent of the germ theory…. [C]learly, modern medical science has helped to clean up the mess created by urban and industrial civilization. However, by the time laboratory medicine came effectively into the picture the job had been carried far toward completion by the humanitarians and social reformers of the nineteenth century. Their romantic doctrine that nature is holy and healthful was scientifically naive but proved highly effective in dealing with the most important health problems of their age. When the tide is receding from the beach it is easy to have the illusion that one can empty the ocean by removing water with a pail. The tide of infectious and nutritional diseases was rapidly receding when the laboratory scientist moved into action at the end of the past century (Dubos, 1959: 107).