Abstract: A modality is a model of “being” from the perspective of the relationship between the copula and modality.The modalities of necessity and possibility are outside of “being”.They are modifiers on sentences.Kant divided the modalities of judgment into the categories of problematic,assertic and adpodictic,and claimed that modalities have no relation with the content of a judgment.Frege regarded the form of necessary judgment as meaningless for the purpose of his concept-script.Freges conception is justified by the meaning of the judgment symbol introduced by him.According to the sense-meaning analysis proposed by Frege,we can give an analysis of modal sentences in which the meaning of a modality is a concept which take a thought as a variable and truth value as the function value.Quines question on the reference-opaque context and the de re modality can also be explained by the meaning of a modality.

Key words: judgment, modality, logic