Sentence, proposition and identity

1. Logical language 1.1. Proposition, sentence and inscription Quine has argued in favor of the rejection of propositions. His argument can be summarized by the following syllogism: No entity without identity There is no criterion of identity for propositions No propositions Quine has been quite influential in the replacement of the expression propositional logic by the expression sentential logic to denote zero-order logic. But do we have a criterion of identity for sentences? And what is a sentence? Some people prefer sentences to propositions, because sentences seem more concrete and definite objects. Nobody has “seen” a proposition, propositions have no smell and no color. But what about sentences? Some people confuse sentences with inscriptions. It was already