ディグナーガにおける“内包”と“外延”

Abstract

"In this paper I elucidate some semantic issues related to the notions of “extension” and “intension” which appear in the Pramāņasamuccaya(-vrtti). The main issue is "extension" of the word "śabda" in the proposition "śabdo 'nityah(Word is non-eternal)". If we regard --and I do-- "śabda" in the proposition as "sarvah śabdah", a problem arises as to the meaning of "sarva(all)". Such an interpretation of a proposition through set as is usually made in predicate logic seems not to be valid for the logic of Dignāga. That is to say, "śrāvaņatva(audibility)" can be a valid logical sign for proof of propositions such as "ayam śabdo 'nityah (This word is non-eternal)", "asau śabdo 'nityah (That word is non-eternal)", etc., whereas it is not a valid sign for proof of the proposition "śabdo 'nityah" in the logic system of Dignāga. If we modified the system of Dignāga we might possibly interpret the "sarvah śabdah" as a set of all śabda(words) and the proposition "śabdo 'nityah" as a total of propositions such as "ayam śabdo 'nityah", "asau śabdo 'nityah", etc. However, I preserve the system of Dignāga, and propose a new kind of notion of "all", which may well be termed "analogical wholeness", to resolve the above-mentioned difficulty. This "wholeness" is obtained by analogy with the notion of set in a collective sense, as was proposed in a set-theory called mereology, which Polish logician Lesniewski invented in 1916. As for "intension", it plays, it seems to me, an important role in the hierarchical structure of words and meanings in the apoha-theory of Dignāga. This issue is touched on slightly in the first and final sections.