The problem with ‘the background logic problem’

Anti-exceptionalism is the view that logic is, among other things, responsive to a posteriori evidence, and that disputes about logic should take adequacy to the data into account. This brings three questions to the fore: i) what counts as evidence in logic? ii) how to determine when evidence favours a particular system of logic, and iii) what kind of logic we use when in such disputes? In this paper, we argue that problem iii), when added to the thesis that natural language does have a specific logic, makes the whole project of logical theory choice untenable. The reason, we shall argue, is that the logic we are supposed to have vitiates any characterization of evidence, making a change of logic unlikely. We do that by studying a case where it is said that evidences favour paraconsistent logic over classical logic, and a case where it is argued that evidences favour a change in the nature of the truth-values (dialetheism). In both cases, the very idea that we have a logic operating in natural language prevent any possibility of change. We then go on and suggest, in broad lines, a version of anti-exceptionalism without the natural language logic hypothesis.


Keywords: logical abductivism; logical theory choice; evidence; paraconsistency; logic of natural language.