Louise Cummings

The world’s scientific community must be in a state of constant readiness to address the threat posed by newly emerging infectious diseases. Whether the disease in question is SARS in humans or BSE in animals, scientists must be able to put into action various disease containment measures when everything from the causative pathogen to route(s) of transmission is essentially uncertain. A robust epistemic framework, which will inform decision-making, is required under such conditions of uncertainty. I will argue that this framework should have reasoning at its center and, specifically, that forms of reasoning beyond deduction and induction should be countenanced by scientists who are confronted with emerging infectious diseases. In previous articles, I have presented a case for treating certain so-called traditional informal fallacies as rationally acceptable forms of argument that can facilitate scientific inquiry when little is known about an emerging disease. In this article, I want to extend that analysis by highlighting the unique features of these arguments that makes them specially adapted to cope with conditions of uncertainty. Of course, such a view of the informal fallacies must at least be consistent with the reasoning practices of scientists, and particularly those scientists (viz. epidemiologists) whose task it is to track and respond to newly emerging infectious diseases. To this end, I draw upon examples of scientific reasoning from the UK’s BSE crisis, a crisis that posed a significant threat to both human and animal health.

Few, if any, scientific inquiries are conducted against a background of complete knowledge, a background in which inquirers are in possession of the ‘full facts’ that relate to a particular question or issue. More often than not, scientists are compelled to conduct their deliberations in contexts of epistemic uncertainty, in which partial knowledge or even a total absence of knowledge characterise inquiry. Nowhere is this epistemic uncertainty more evident, or indeed more successfully controlled, than in the branch of scientific inquiry called epidemiology. In this paper, I examine how epidemiologists overcome the unique challenges to inquiry that are posed by epistemic uncertainty. In specific terms, I contend that epidemiologists employ analogical reasoning strategies in an attempt to advance their inquiries in situations that are epistemically uncertain. The context for my claims will be the early inquiries that were conducted into the emergence of HIV/AIDS in the United States. I argue that early scientific work in relation to HIV/AIDS was directly premised upon epidemiological investigations in which analogical reasoning with hepatitis B had featured significantly. I conclude that epidemiological investigations of AIDS exemplify the capacity of analogical reasoning to advance inquiry under conditions of epistemic uncertainty. To this extent, analogical reasoning should be a concern both to those who address practical problems of uncertainty management and to those who pursue theoretical debates within argumentation studies and epistemology.

The study of the fallacies has changed almost beyond recognition since Charles Hamblin called for a radical reappraisal of this area of logical inquiry in his 1970 book Fallacies. The “witless examples of his forbears” to which Hamblin referred have largely been replaced by more authentic cases of the fallacies in actual use. It is now not unusual for fallacy and argumentation theorists to draw on actual sources for examples of how the fallacies are used in our everyday reasoning. However, an aspect of this move towards greater authenticity in the study of the fallacies, an aspect which has been almost universally neglected, is the attempt to subject the fallacies to empirical testing of the type which is more commonly associated with psychological experiments on reasoning. This paper addresses this omission in research on the fallacies by examining how subjects use two fallacies – circular argument and analogical argument – during a reasoning task in which subjects are required to consider a number of public health scenarios. Results are discussed in relation to a view of the fallacies as cognitive heuristics that facilitate reasoning in a context of uncertainty.