文脈主義にとっての真理と意味
Truth and Meaning for Contextualism
水本正晴 Masaharu Mizumoto
北陸先端科学技術大学院大学 JAISTIn this paper I shall argue that Wittgensteinian contextualist cases (a la Travis andothers) and Gettier cases in epistemology are two sides of the same coin, or theconsequences of the existence of what I call contextually loaded proposition. Oneand the same sentence can express two (or indefinitely many) different contextuallyloaded propositions, depending on the context, and while in contextualist cases suchpropositions have different truth conditions (with different truth values), in Gettiercases they share the same truth condition. I will argue for the existence of suchcontextually loaded propositions through careful considerations of Gettier cases.
There are two important consequences of it: One is that, despite recent criticism(Whiting 2011), contextualism is indeed inconsistent with deflationism about truth,
as Travis has long insisted. Another consequence is that, since this kind ofproposition is independent of truth condition, Travis’s formulation of thecontextualism in terms of truth condition (e.g. in his 1997) is misguided, and theproject like truth-conditional pragmatics, by the fellow contextualist Recanati(Recanati 2010), is also doomed. I will sketch how the contents of belief andsentence are to be naturally individuated, which in turn explains why the concept ofknowledge seems primitive. (This paper is a natural extension of the papers
presented last two years in this conference, which together constitute a
prolegomena of what I called elsewhere the knowledge-first semantics.)
1. Background: Contextualism is a thesis that it is “intrinsically part of what
expressions of [natural language] mean” (Travis 1997, p.87) that a given sentence
can express indefinitely many different propositions depending on the context (evenwithout any indexical element). This may be taken as one of the consequences ofWittgenstein’s thesis of meaning as use. Charles Travis has argued forcontextualism, with numerous interesting examples, in his papers and books (e.g.
Travis 1996, 1997, 1989, 2006).
2.

Arguments

forContextually Loaded Propositions:Contextualists

havecharacterized the contextually determined propositions in terms of truth conditions,as if propositions are individuated by truth condition. Against this, I will argue thatdifferent truth conditions entail different propositions, but not vice versa, and thecontext itself is involved in such propositions in an important sense (in particular,

how it came to being, its history, is involved as part of what it is, its content.),
through the following three observations of Gettier cases;
1) In standard Gettier cases the belief in question has content intuitively different
from that of possible genuine knowledge in the same situation, while they justhappened to share the same truth condition.
2) The description of lucky cases with indexicals demonstrates the case of different
contents sharing the same truth condition, though they are standardly taken as thecases of different “characters” with the same content, and contextualism is thegeneralization of such context-dependency to non-indexical cases.
3) The existence of mathematical Gettier cases implies that the content of relevant
belief in such cases is different from that of corresponding mathematical sentence.
For, the former is accidentally true, while the latter is necessarily true.
3. Natural Individuation of Content and Truth Condition: Against 1), however, one
may respond that the same cannot be said to the fake barn case and its variants.
Against 2), one may still wonder how we can individuate the content independentlyof its truth condition. Against 3), one may respond by distinguishing the epistemic
property of truth from semantic property of truth, taking the accidentality of thetruth in Gettier cases as an epistemic property. To worries about 1) and 2), I willanswer by appealing to the natural pattern of belief retraction, which naturallyindividuates the content of belief (and derivatively, that of other truth-bearers), anddoing so dissolves the distinction of the metaphysical necessity and the epistemicnecessity implicitly assumed in the response to 3).
4. Deflationism: The existence of such contextually loaded propositions falsify
deflationism by posing a dilemma: When the right-hand side sentence is used(rather than mentioned) to express the contextually loaded proposition,
contextualist

cases

would

triviallyfalsify

the“only-if”-directionofthedisquotational version of T-Schema (DS) unless the context is fixed constantthroughout the two sides of the bi-conditional. If, on the other hand, the context isfixed throughout the bi-conditional, which is by definition the case in thepropositional schema (PS), T-Schema (whether DS or PS) effectively eliminates any

accidental truth whatsoever. Indeed, it eliminates all the Gettier cases by rendering
all the relevant beliefs in them false. Thus either way, T-Schema should be judged
false, at least for the folk concept of truth.