realism is abandoned, not because a truth-conditional account of the meanings of the statements is impossible, nor, necessarily, because there is any reason to repudiate the principle of bivalence
as applied to them, but because the notion of reference no longer plays any role in the account of their meanings.
The principle of bivalence, concerning statements of the object-language, is easily statable in a theory of truth and it may or may not be a theorem of the theory.
As for the principle of bivalence, it does seem likely that it cannot be a theorem of a verificationist theory of meaning (if only because it cannot be expressed therein), but this needs argument and, besides, the principle of bivalence, while important, is not the same as realism.
He complains, with some justification, that Dummett's earlier explanations of what realism is had run this principle together with the principle of bivalence. Wright (1987, p.
In De Interpretatione 6-9, Aristotle considers three logical principles: the principle of bivalence
, the law of excluded middle, and the rule of contradictory pairs (according to which of any contradictory pair of statements, exactly one is true and the other false).