Evidence and Argument Evaluation

Abstract

This chapter confronts the central problem in the current state of argumentation studies, that of clarifying the relationship between argument and evidence. This problem was posed in Chaps. 5 and 6, where the notions of argument and evidence were notably prominent in the use of forensic evidence in the case of the Leonardo Da Vinci portrait and also in the examples of evaluating scientific arguments from correlation to causation. It remains open to be seen how evidence is related to argument generally, as part of the project of argument evaluation. Because this is such a pervasive issue of high generality, it has been reserved for the last chapter. The solution proposed is to fit six argumentation schemes for epistemic defeasible reasoning into a cluster of schemes enabling the basic evidence in a case to generate indirect evidence by using other schemes. This division helps to explain an ambiguity in the use of the term ‘evidence’. Used in a broader sense, ‘evidence’ can include any argument presented to support or attack a claim. In a narrower sense, ‘evidence’ refers to particular kinds of arguments, such as those based on observations, factual findings, statistics, experimental tests or other scientific findings.