オッカム『論理学大全』(III-1, c. 5) における様相概念について

In this paper, we have followed the arguments presented in the examples in Ockham, Summa Logicae, III-1, c. 5. The discussion is based on the assumption that there is a person who knows only ‘gladius’ but not ‘ensis’, and does not know that ‘gladius’ and ‘ensis’ are synonyms. In such a case, Ockham maintains that the modal proposition ‘ensis scitur a Sorte esse unum genus armorum’ is true. We have traced the argument that this proposition is true, which is based on the distinction between compositio and divisio. The theory of modalities developed by Ockham in Summa Logicae has been evaluated to be related to the problems of ‘opaqueness of indication’ and ‘propositional attitude’ in the analytic philosophy. Therefore, it is not a waste of time to reconstruct Ockham’s discussion.