指示の理論と信念変化(Theory of Reference and Belief Change)
水本正晴（Masaharu Mizumoto）
北陸先端科学技術大学院大学(JAIST)(※発表は日本語で行います)
1. Background: One’s view on reference seems to have direct implications fordebates in various fields of philosophy (Machery et al. 2007). However, some people(Chomsky 1993, 1995, Stich 1996, etc.) have expressed skepticism about the theoryof reference in general. Indeed, even the question of what the theory of reference issupposed to do does not have a straightforward answer (Stich 2009). A related
question is the role of folk intuitions. Let us suppose that the job of the theory ofreference is to describe the tacit theory of the relation behind such intuitions, or“folk semantics” (cf. Stich 2009) of referential terms. Such a position alreadyinvites skepticism about the linguistic normativity, and if, as many philosophersassume, meaning is essentially normative, then this skepticism extends tomeaning. Thus, denying the reality of shared linguistic norms, Davidson (1990)
and Chomsky (1995) claimed that there is no such thing as language or languages.
Here we are actually sympathetic with skepticism of Stich and Chomsky about thetheory of reference. There should be no unique “correct” or “true” theory ofreference. But that is not because we are skeptical about the linguistic normativity.
2. Cultural Variance of Reference?: The seminal work that claims to show thecultural variance of linguistic intuitions about reference is Machery et al (2004).
There have been however a number of (and mostly right) criticisms already thrown
against it (Ludwig, 2007, Lam 2009, Deutsch 2009, Ichikawa et al., forthcoming).
The most relevant here is the lack of clear distinction between the speakerreference and semantic reference. The theory of reference should be concernedwith the latter, not the former, but we rather claim that the very possibility of thegap here in fact constitutes the normativity itself: For those who lack such a
distinction there is no relevant linguistic normativity. Then exactly where thepossibility of this gap or the normativity of reference consists in?
3. Psychologizing Fregean Sinn: Let us first carefully distinguish Frege’s Sinn as 1)
a “mode of presentation” (the Evans-McDowell object-dependent de re sense(McDowell 1984)) and 2) a “way of determining” a Bedeutung. 1) may be further
re-interpreted as an “aspect” of the object in Wittgenstein’s sense. But the moregeneral sense of Sinn is 2). If, however, we take it literally, as a “procedure ormeans one can carry out for determining the Bedeutung”, then when extended tothe Gedanke, it entails verificationism (Klement 2002, p. 60).
4. Sinn as Practical Knowledge: Instead, we propose here to take a Sinn in ths1

sense as a part of the content of practical knowledge in the sense of Anscombe(1957), that knowing what one is doing. Thus the sense (Sinn) of a word is what
one has (understand) when and only when one knows what one means by the word.
In other words: For any expression e, and any person S, what e means for S is what
S believes e to mean when and only when S knows what e means. Note here that,(1) “what e means for S” does not necessarily imply that this is about the speaker
meaning, as long as it can be distinguished from what S intends to mean by e, and(2) this formulation is supposed to apply to linguistic expressions quite generally,
like proper names, natural kind terms, and any other nouns, or even verbs.
5. Normativity and Knowledge: Just as Anscombe’s practical knowledge, where wemay be mistaken about what we are doing, we may also be mistaken about what
we mean by e. This possibility is what constitutes the linguistic normativity, whichis also a gap between thinking that one is following a rule and in fact following therule. In the case of practical knowledge, we should distinguish it from knowledge ofthe content of intention: one may fail to know what one is doing, while one stillknows what one intended to do.
6. Reference and Belief Change: According to what I called the sustainability
analysis of knowledge in my (2011), knowledge is belief that is sustainable against
actual information. For example, suppose that, S believes that S is following rule R.
If this belief is sustainable, i.e., whatever actual information in the world does notmake S retract the belief, then S knows that S is following rule R. If not, upon some
information, S’s belief naturally changes and the belief in question will be given up.
Then let us look at how the account of reference looks like according to thisanalysis, by Kripke’s Gödel/Schmitt case used in Machery et al. (2004). Suppose, inthat vignette, the person who newly learned about Gödel and the incompletenesstheorem before, says “Gödel is a genius”. Then she finds that actually Schmitt had
proved the theorem and Gödel stole it. Which would be her reaction? The naturalchange of her belief is either to 1) retract her belief that Gödel is a genius (thecausal-historical account), while knowing who “Gödel” refers, or 2) retract her
belief that the name of the person who proved the incompleteness thesis is Gödel
and therefore did not know who his “Gödel” was referring to (the descriptiontheories). The possibility like 2 constitutes the normativity of reference (the gapwith intention). The choice between 1 and 2 is, however, not a matter of which istrue, or what the correct theory of reference dictates. It just depends on the context,
the background belief of the speaker, and even the culture, or simply everythingthat is relevant to the possible belief change concerning these beliefs. This alsomeans that the normativity of reference itself may vary depending on the context,
culture, etc. In other words, there is no such thing as the “correct” theory ofreference that determines which of 1 and 2 is right. The present account instead
explicates the (meta-semantic) fact of a linguistic expression meaning something.
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