karl popper's philosophy of science has done what it requires a good scientific hypothesis to do—it has proved its mettle. This success creates a difficulty for a contributor to a Festschrift for him. This chapter shows that Hempel's view has unfortunate implications similar to those which Popper has extracted from the majority view. It also shows that it makes metaphysical hypotheses "confirmable," and in that it makes the exact hypotheses of mathematical physics "unconfirmable." The chapter argues that Popper's falsificationist theory of corroboration does not involve the "paradoxes of confirmation" which Hempel's verificationist theory involves. It utilizes the results against positivism. The chapter introduces the idea of a degenerating series of hypotheses, the first and strongest entailing, but not being entailed by, the second, the second entailing but not being entailed by the third, and so on. Hempel himself expressed misgivings about this "adequacy-condition.".