Two Purposes of Arguing and Two Epistemic Projects

Abstract This chapter borrows what Frank Jackson says about propounding arguments, a phenomenon in the dialectical domain, and transposes it to the epistemological domain. It seeks to clarify the notion of transmission of epistemic warrant and, particularly, the idea of failure of warrant transmission (transmission failure). In this transposition there will be, corresponding to the two purposes of arguing, two kinds of epistemic project. These are referred to as deciding what to believe (corresponding to the teasing-out purpose of arguing) and settling the question (corresponding to the convincing purpose). For each kind of epistemic project, there will be a property of arguments that makes an argument ill-suited for use in projects of that kind. Each property might be called ‘transmission failure’. The two accounts of transmission failure (one analogous to Copi's account of begging the question and the other to Jackson's) provide principled limitations on the arguments that can properly be used in pursuing epistemic projects of the respective kinds (deciding what to believe and settling the question).