著者

西脇 与作 藁谷 敏晴

出版者

慶應義塾大学

雑誌

哲學 (ISSN:05632099)

巻号頁・発行日

vol.65, pp.23-49, 1977-01

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1. logical valueの論理 : 存在論的価値 1.1. 文、真理値、存在の相互関係 1.2. 真理値と2値性 1.3. 結合子としての同一性記号2. W-言語と理論3. SCIの諸性質 3.1. SCIの基本的定理 3.2. 論理評価と指示 3.3. 論理評価の種類4. SCIの拡張 4.1. 中間的諸システム 4.2. 拡張の過程In this paper, " non-Fregean logics " proposed by R. Suszko are studied ; 1. from a philosophical point of view concerning the necessity of introducing the identity-connective, and 2. from technical point of view concerning logical structure of non-Fregean logics. Analysing the Frege's ambiguity in treating the logical constants 1,0 (in Frege), we were led to the conclusion ; 1) A distinction between valuational two valuedness and ontological (referential) two-valuedness should be made, 2) keeping the valuational two-valuedness (the principle of bivalence), the abolition of ontological one is possible (ontological many-valuedness), 3) in order to express logical systems based on valuational two-valuedness and ontological many-valuedness, the introduction of identity-connective is unavoidable. Such logics have been studied among others by R. Suszko as theories of kind W, and its sentential part is called SCI (sentential calculus with identity). In this paper, our interest was directed esp. on 1) logical relations between SCI, SC (sentential calculus) and there intermediate variaties, 2) A possibility of introducing some meta-notions into object languages, 3) some valuations of non-Fregean languages.