Analogical reasoning in public health

Analogical reasoning is a valuable logical resource in a public health context. It is used extensively by public health scientists in risk assessments of new technologies, environmental hazards and infectious diseases. For its part, the public also avails of analogical reasoning when it assesses a range of public health problems. In this article, some of these uses of analogical reasoning in public health are examined. Analogical arguments have courted approval and disapproval in roughly equal measure by a long succession of logicians and philosophers. The logical features of these arguments which make them simultaneously compelling and contemptible are considered. As a form of presumptive reasoning, analogical arguments have a valuable role to play in closing epistemic gaps in knowledge. This heuristic function of these arguments is illustrated through an examination of some uses of analogical reasoning in recent public health crises. Finally, the results of a study of analogical reasoning in 879 members of the public are reported. This study reveals that lay members of the public are able to discern the logical and epistemic conditions under which analogical arguments are rationally warranted in a public health context.