Philosophy and Public Health

In order to develop a new theory of reasoning, public health must embrace certain logical and epistemological concepts which have almost exclusively been examined within philosophy. These concepts include presumption and a group of arguments known as the informal fallacies. It is argued that presumption is a highly versatile concept which has not received the attention it deserves in epistemology. Features of this concept such as its defeasibility make it well suited to reasoning in contexts of uncertainty. However, in order to achieve any purchase in reasoning, presumption must find a logical home. It is argued that that home is as part of a group of arguments known as the informal fallacies. Throughout the long history of logic, informal fallacies have been characterized as weak or bad forms of reasoning. However, with the emergence of informal logic, traditionally negative characterizations of these arguments have lost some of their dominance. The journey taken by these arguments, from their treatment in the logical treatises of historical thinkers to present-day analyses, is examined in this chapter.