Verificationism

Verificationism, also called the verification principle, is a position within the philosophy of science and language associated with the logical positivist movement, holding that a statement is meaningful only if it is either analytically true by definition or logic, or empirically verifiable in principle through observation or experiment; any statement meeting neither condition, the position holds, is strictly meaningless rather than merely false or unproven. The principle was developed and championed chiefly by members of the Vienna Circle, a group of philosophers and scientists active in Vienna beginning in the 1920s, with philosopher Moritz Schlick and later A. J. Ayer, whose accessible 1936 book Language, Truth and Logic popularized the position for English-speaking audiences, among its most prominent proponents. Verificationism was intended to draw a sharp line excluding metaphysical, theological and much ethical language as literally meaningless, since such statements typically cannot be empirically verified even in principle. The principle came under sustained philosophical criticism from the mid-twentieth century onward, notably for the self-referential difficulty that the verification principle itself is not empirically verifiable by its own stated standard, and it was substantially superseded within philosophy of science by Karl Popper's alternative falsifiability criterion.