'Among its many merits, this remarkable book deserves to become a classic text in the philosophy of science. Almost alone among philosophers of science, Noble is a practising scientist; and unusually among practising scientists, he is an accomplished philosopher. His book brings out, with unparalleled clarity, how the scientific endeavour involves not only empirical inquiry but also conceptual structure. Noble shows how, on the negative side, popular presentations of sound biological results may be vitiated by bad metaphysics, and how, on the positive side, science and philosophy may extend the boundaries of knowledge by a unified epistemology. He ends, however, with a salutary warning that there may well be a limit to the human capacity to know the answers to ultimate questions.' Sir Anthony Kenny, University of Oxford