Vol.:(0123456789) 1 3 Topoi https://doi.org/10.1007/s11245-020-09694-2 Varieties of Deep Epistemic Disagreement Paul Simard Smith 1  · Michael Patrick Lynch 2 © Springer Nature B.V. 2020 Abstract In this paper we discuss three diferent kinds of disagreement that have been, or could reasonably be, characterized as deep disagreements. Principle level disagreements are disagreements over the truth of epistemic principles. Sub-principle level deep disagreements are disagreements over how to assign content to schematic norms. Finally, framework-level disagree- ments are holistic disagreements over meaning not truth, that is over how to understand networks of epistemic concepts and the beliefs those concepts compose. Within the context of each of these kinds of disagreement it is not possible for the par- ties to the dispute to rationally persuade one another through only ofering epistemic reasons for their conficting points of view. However, in spite of the inability to rationally persuade, we explore how it may nevertheless be possible to rationally navigate each of these varieties of deep disagreement. Keywords Deep disagreement · Peer disagreement · Epistemic rationality · Cogency · Incompletely theorized agreement 1 Introduction Broadly speaking, disagreements are worth calling “deep” to the extent they are not just deadlocked, but they’ve reached a point—a depth—where the subject of the disagreement is fundamental. A disagreement is “epistemic” when it is about something overtly epistemic in character. For example, when it is about whether a proposition is justifed or an epistemic principle is true. Deep epistemic disagreements are disagree- ments with both features. 1 Within the existing social epistemic and argumentation theoretic literature a variety of diferent kinds of disagree- ments either have been—or could reasonably be—charac- terized as deep. That raises the question of whether, and to what extent, these diferent kinds of disagreements refect disagreement about the nature of deep disagreement or are instead highlighting importantly diferent phenomena. In this paper, we discuss three diferent kinds of disagreement characterized by Goldman (2010), Lynch (2010, 2016) and Fogelin (2005) respectively. We make the case that, within the context of each of these kinds of disagreement, there is a breakdown in the prospects of rational persuasion through the give and take of epistemic reasons. In particular, we claim that, in each of these forms of disagreement, the pros- pect of one party ofering an argument in support of their point of view that is epistemically cogent for the other party is substantially constrained. So, while the various kinds of disagreements that we consider here are distinct, they are variations on a common theme. Each kind of disagreement undermines the prospects of a resolution to the disagree- ment through an exchange of purely epistemic reasons— even though the reasons why each disagreement undermines the prospects of such a resolution varies for each case. It is this common theme that makes these kinds of disagreements worth calling deep, highlights their importance and encour- ages us to fnd new strategies for navigating them. * Paul Simard Smith Paul.Simard.Smith@uregina.ca Michael Patrick Lynch mplynch@uconn.edu 1 Department of Philosophy and Classics, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada 2 Department of Philosophy, University of Connecticut, U-1054, Storrs, CT 06269-2054, USA 1 Unless we explicitly state otherwise, when we use the expression ‘deep disagreement’ we are referring to deep epistemic disagree- ments.