Bergen Logic Seminar: Epistemic Overdetermination Strikes Back: A New Hope for the A Priori

Epistemic Overdetermination Strikes Back. A New Hope for the A Priori

Abstract

Recent work in the epistemology of logic has taken an empiricist turn in the understanding of its subject matter. Two key Quinean intuitions have been embraced by logical anti-exceptionalists: that i) logical theorizing is non-exceptional – not special – and contiguous to science; ii) that logical theories are justified and adopted via abductive methodology (e.g., inference to the best explanation), which in turn is based on scientifically constrained premises that concern theoretical virtues. I argue that an indispensable feature of this methodology cannot be coherently accounted by anti-exceptionalists: epistemic overdetermination, i.e., the phenomenon according to which the same logical claim can be justified on the basis of multiple sources of evidence, including both a priori and a posteriori ones. I contend that logical anti-exceptionalist should either revise their epistemic framework to allow for a defeasible notion of a priori justification or avoid relying on a priori evidence altogether. However, each of these strategies has its own drawbacks: anti-exceptionalists about logic can account for epistemic overdetermination – and, consequently, for an empiricist epistemology of logic – only if they either recognize that logic can be a priori justified, or they admit the implausible claim that some crucial criteria underlying the inference to the best explanation should be abandoned, e.g., the adequacy to the data criterion.