 This reluctance is probably due to the fact that idealism is most often identified with immaterialism and he would not have wished his criticism of realism to be interpreted as resting on a commitment to the claim that the real is ideal or that mind is causally responsible for the existence of reality. If the contrast between idealism and realism is understood as one between two metaphysical views concerning the ontological constitution of reality (is it mental? Is it material?) Collingwood had nothing to contribute to the debate between realists and idealists; he would have regarded it as belonging to metaphysics as the study of pure being, not as metaphysics understood as a form of presuppositional analysis. In An Autobiography (1939) he contrasted realism not with immaterialism but with the commitment to presuppositionless knowledge or the realist view propounded by Cook Wilson and Prichard that “knowing makes no difference to what is known” (AA 2013: 44). Denying realism, so understood, is to deny that there can be any such thing as knowledge of pure being. Since all knowledge takes the form of answers to questions, and all questions rest on presuppositions, knowledge necessarily has presuppositions. Collingwood’s critique of realism therefore takes Kant’s criticism of the possibility of knowing things as they are in themselves a step further. Kant did not deny that talk about knowledge of things as they are in themselves is coherent; he simply claimed that this sort of knowledge is unavailable to us. Collingwood’s critique of realism, by contrast, denies that there is any such thing as presuppositionless knowledge. Presuppositionless knowledge is not a kind of knowledge that it is not possible for us to acquire but may be available to another being, such as God: the idea of presuppositionless knowledge involves an oxymoron because all knowing involves presuppositions.