The public health tool kit has expanded in recent years. For much of the period since the second world war, epidemiology has been its technical tool par excellence. But recently the role of epidemiology has been questioned, and its shortcomings have been highlighted. Epidemiologists have been establishing scientific alliances with other disciplines; the rise of genetics within public health is the most prominent example. The connections with social science have a long history and go back to the emergence of a separate medical sociology in the postwar years.1

History, too, is emergent as part of the public health tool kit. However, as Perdiguero and his colleagues remind us in this issue (see page 667), this is a re-emergence rather than a totally new development. In the 18th and 19th centuries there were mutual relations between history and epidemiology. At my own institution in the interwar years, the leading epidemiologist Major Greenwood taught both history and epidemiology to the students. Since then history has retained a foothold in public health, and tends to be used in two main ways. There is the “great man” school of history that looks to the past for inspiration. Edwin Chadwick or John Snow and their battle with disease provide a model for the present, for the developing countries' need for …