verifiability theory of meaning See MEANING, PHI -. LOSOPHY OF LANGUAGE , VERIFICATIONIS. verificationism, a metaphysical theory about what determines meaning: the meaning of a statement consists in its method(s) of verification. Verificationism thus differs radically from the account that identifies meaning with truth conditions, as is implicit in Frege’s work and explicit in Wittgenstein’s Tractatus and throughout the writings of Davidson. On Davidson’s theory, e.g., the crucial notions for a theory of meaning are truth and falsity. Contemporary verificationists, under the influence of the Oxford philosopher Michael Dummett, propose what they see as a constraint on the concept of truth rather than a criterion of meaningfulness. No foundational place is generally assigned in modern verificationist semantics to corroboration by observation statements; and modern verificationism is not reductionist. Thus, many philosophers read Quine’s ‘Two Dogmas of Empiricism’ as rejecting verificationism. This is because they fail to notice an important distinction. What Quine rejects is not verificationism but ‘reductionism,’ namely, the theory that there is, for each statement, a corresponding range of verifying conditions determinable a priori. Reductionism is inherently localist with regard to verification; whereas verificationism, as such, is neutral on whether verification is holistic. And, lastly, modern verificationism is, whereas traditional verificationism never was, connected with revisionism in the philosophy of logic and mathematics (e.g., rejecting the principle of bivalence). See also LOGICAL POSITIVISM , MEANING, PRINCIPLE OF VERIFIABILITY , VIENNA CIRCL. E.L.