Anyone who’s even heard of Popper knows that he advanced his falsifiability criterion (of science) in opposition to the Vienna Circle’s verifiability criterion (of meaning). What the Popper fans seem unaware of (yes, I know, they’re no longer as numerous as in the days of Helmut Schmidt’s public endorsement) is that Carnap actually responded to this criticism by pointing out that you can’t distinguish between verification and falsification except in certain special cases, which happen not to include the laws of e.g. physics. That was in “Testability and Meaning” (1936-7), which Popper praised volubly, e.g. in his Schilpp volume. But despite the fatal consequences of Carnap’s argument for Popper’s whole edifice, Popper never responded, nor, as far as I’m aware, has any of his followers. Continue reading →