On the Usefulness of Rigidity and Two Possibilities

コテイセイ ガイネン ノ ユウヨウセイ ト フタツ ノ カノウセイ ニツイテ

モトヤマ, アスカ

Motoyama, Asuka

オオサカ ダイガク ダイガクイン ニンゲン カガク ケンキュウカ シャカイガク ニンゲンガク ジンルイガク ケンキュウシツ

Sociology, Anthropology and Philosophy, Graduate School of Human Sciences, Osaka University

ソール・クリプキ

記述主義

一般名辞

二つの可能性

rigidity

Saul Kripke

descriptionism

general terms

two possibilities

This paper claims that Saul Kripke’s notion of rigidity is related to two kinds of possibilities and that the discussion between Joseph LaPorte and Stephen P. Schwartz is not fruitful, because they miss this nature of rigidity. In Naming and Necessity, Saul Kripke argued about the notion of rigidity for proper names. Recently LaPorte and Schwartz have discussed about the applicability of this notion to general terms. But in this discussion, their positions are totally opposite. Particularly in the problem concerning the referents of general terms, their views shows a great difference. What is crucial in this opposition is the lack of sufficient understanding about some important aspects of rigidity. Firstly in Kripke’s explanation the notion of rigidity underlies our intuitive understanding about possibilities and holds the relations between names and objects. Secondly rigidity relates two kinds of possibilities, which are the epistemic possibility and the metaphysical possibility. Thirdly rigidity is needed only for the latter, metaphysical one. But both LaPorte and Schwartz understand rigidity in relation to one of two possibilities. LaPorte's understanding about rigidity belongs to metaphysical possibility and Schwartz's to epistemic one. Lastly I will claim that it is very difficult to formalize the notion of rigidity, because this notion is very intuitive in its original version.