Two Kinds of Partial Truth

Session chaired by : Jean-Baptise Rauzy (Sorbonne University)

Abstract

In "Aboutness", Yablo writes that "a statement S is partly true insofar as it has wholly true parts". Thus, to be partly true is to have some part that is wholly true. Call this an extensive characterization of the notion of partial truth. In this talk I propose to discuss whether the extensive characterization captures all senses of partial truth. Some cases of partly true statements appear to match a different characterization. Arguably, some partially true statements consist of an integral part that is only half-true. This suggests a more intensive notion of partial truth. An analogy may help to get the difference: a surface may be described as "partly blue" when some portion of it is fully blue; or a surface may be described as "to some extent blue" when all its parts are mixed blue (viz. blue-green). In the case of partial truth, the intensive characterization assumes that truth could be a gradable notion, whereas the extensive characterization can stick to the idea that truth is fundamentally non-gradable. How do the two notions relate? One option is to consider that the intensive notion of truth degree fundamentally supervenes on the extensive notion. Another is to admit that the intensive notion might not be reducible. To subsume both in this case, a possibility I will discuss is to weaken Yablo's definition, and to say that a statement is partly true if it has parts that are true to some degree.

Paul Egré

Paul Egré is directeur de recherche at Institut Jean-Nicod (CNRS, EHESS, ENS) and Professor in the Department of Philosophy of École normale supérieure (PSL University). His research deals with logic, philosophy of language, and epistemology. A significant part of Egré's work concerns the treatment of vagueness in language and in perception, some of it involving interdisciplinary work in psychology and cognitive science. A few of his recent publications are: Qu'est-ce que le vague ? (Vrin, 2018) and "Half-truths and the Liar" (in Modes of Truth, C. Nicolai and J. Stern editors, Routledge, 2021).