A moderate belief-disagreement between agents on proposition p means that one agent believes p and the other agent does not. This paper presents two logical systems, \ and \, that describe moderate belief-disagreement, and shows, using possible worlds semantics, that \ is sound and complete with respect to arbitrary frames, and \ is sound and complete with respect to serial frames. Syntactically, the logics are monomodal, but two doxastic accessibility relations are involved in their semantics. The notion of moderate belief-disagreement, (...) which is in accordance with the understanding of belief-disagreement in everyday life, is an epistemic one related to multiagent situations, and \ and \ are two epistemic logics. (shrink)

Scientists often diverge widely when choosing between research programs. This can seem to be rooted in disagreements about which of several theories, competing to address shared questions or phenomena, is currently the most epistemically or explanatorily valuable—i.e. most successful. But many such cases are actually more directly rooted in differing judgments of pursuit-worthiness, concerning which theory will be best down the line, or which addresses the most significant data or questions. Using case studies from 16th-century astronomy and 20th-century geology and (...) biology, I argue that divergent theory choice is thus often driven by considerations of scientific process, even where direct epistemic or explanatory evaluation of its final products appears more relevant. Broadly following Kuhn’s analysis of theoretical virtues, I suggest that widely shared criteria for pursuit-worthiness function as imprecise, mutually-conflicting values. However, even Kuhn and others sensitive to pragmatic dimensions of theory ‘acceptance’, including the virtue of fruitfulness, still commonly understate the role of pursuit-worthiness—especially by exaggerating the impact of more present-oriented virtues, or failing to stress how ‘competing’ theories excel at addressing different questions or data. This framework clarifies the nature of the choice and competition involved in theory choice, and the role of alternative theoretical virtues. (shrink)

This book presents an original discussion and analysis of epistemic peer disagreement. It reviews a wide range of cases from the literature, and extends the definition of epistemic peerhood with respect to the current one, to account for the actual variability found in real-world examples. The book offers a number of arguments supporting the variability in the nature and in the range of disagreements, and outlines the main benefits of disagreement among peers i.e. what the author calls the benefits to (...) inquiry argument. (shrink)

Predicates of personal taste have attracted a great deal of attention from philosophers of language and linguists. In the intricate debates over PPT, arguably the most central consideration has been which analysis of PPT can best account for the possibility of faultless disagreement about matters of personal taste. I argue that two models of such disagreement—the relativist and absolutist models—are empirically inadequate. In their stead, I develop a model of faultless taste disagreement which represents it as involving a novel incompatibility (...) relation between preferences that I call type-noncotenability. This model is available to all parties in the ongoing debates about PPT, but it points up an advantage enjoyed by expressivist accounts of PPT. In closing, I consider four objections against the model that, while failing to fully undermine it, open up promising avenues of inquiry about the nature of disagreement. (shrink)

This article examines the central epistemological issues tied to the recognition of disagreement.