Abstract

This chapter suggests that evidence should be viewed as a field of study, one to which most disciplines could contribute and from which most could benefit, and that generalisations should be viewed as part of that field. Every argument must be based upon a generalisation that can be stated as a major premise. The relationship between a supporting proposition or propositions and an inferred proposition can be restated in a quasi-deductive form by identifying the generalisation upon which the inference depends. A datum or a proposition can be evidence if and only if it alters the probability, positively or negatively, of a proposition to be inferred. In order to demonstrate that an evidential proposition is relevant, an analyst must be able to identify and articulate a generalisation that justifies the claim that the evidential proposition alters the probability of an inferred proposition. This chapter develops these ideas and presents a method of generalisation-analysis. It also argues that generalisation-analysis is a tool in the field of evidence that could be useful in analysing and critiquing arguments in many disciplines.