Некоторые особенности первопорядковой кванторной логики знания и мнения.

Abstract

In the paper some general traits of First-order Logic of knowledge and belief are discussed. As soon as such Logic is built as specific modal logic with epistemic and doxastic modal operators, rules of universal instantiation, existential generalization and substituteity of identity must be modified with order to avoid well-known modal paradoxes. It is proposed in the paper to consider as genuine singular terms only individual descriptions for which epistemic (or doxastic) existence is proved. Such descriptions are used with appropriate contextual definitions that differ from definitions of Russel’s theory. No modal paradoxes arise under approach proposed.