ABSTRACT
According to the presuppositional model, a conceptual scheme is not identical with a sentential language, but is a set of M-presuppositions of a P-language. Thus, sentential-language translatability can no longer be used as a criterion of the identity of conceptual schemes. D. Davidson's argument from translatability against radical conceptual relativism becomes powerless in front of the presuppositional model. I. Hacking clearly identifies the very root of both the received interpretation of incommensurability as untranslatability and the Quinean notion of conceptual schemes: neglect of truth-value status and denial of possible truth-value gaps between two incommensurable languages. Hacking fundamentally opposes the received interpretation of incommensurability because 'the idea of incommensurability has been so closely tied to translation rather than reasoning'. Through the introduction of the notion of styles of scientific reasoning, Hacking starts to explore an alternative interpretation that focuses on truth-value status along the line of trivalent semantics.
