 First, Popper claims to be a realist and rejects conventionalist and instrumentalist accounts of science. But his account in the Logic of Scientific Discovery of the role played by basic statements in the methodology of falsification seems to sit uneasily with that. As we have seen, he follows Kant in rejecting the positivist/empiricist view that observation statements are incorrigible, and argues that they are descriptions of what is observed as interpreted by the observer with reference to a determinate conceptual and theoretical framework. He accordingly asserts that while basic statements may have a causal relationship to experience, they are neither determined nor justified by it.