This chapter aims to explain Collingwood’s doctrine of absolute presup positions as outlined in An Essay on Metaphysics (EM). In particular I wish to establish whether Collingwood’s doctrine of absolute presuppositions is psychological in nature and whether EM can be described, in Donagan’s terms, as a kind of ‘depth psychology’. 1 I will attempt to settle this question by considering the relationship in which Collingwood’s doctrine of absolute presuppositions stands to the project of naturalised epistemology. This investigation of the relationship between Collingwood’s descriptive metaphysics and the project of naturalised epistemology has been prompted by the fact that the most damaging charge levelled against EM, the charge of historicism or historical relativism, is based on the erroneous assumption that EM has abandoned the project of the justification of knowledge claims in favour of a much more limited inquiry into the origins of belief. I wish to establish, first, that Collingwood’s doctrine of absolute presuppositions is based on a transcendental argument that is Kantian in provenance and, second, that to the extent that the doctrine of absolute presuppositions avails itself of a transcendental argument, it is concerned with the quid iuris, the question of our entitlement or justification for holding certain beliefs, not the question of their origin. The chapter is divided in three sections. In the first I contrast epistemological naturalism with epistemology traditionally understood and argue that they are two rather different kinds of enterprise: traditional epistemology is a normative inquiry concerned with the question of the justification of beliefs, while naturalised epistemology is a genetic inquiry concerned with the origin of belief. In the second I clarify the notion of a transcendental argument. In the third section I outline Collingwood’s doctrine of absolute presuppositions and argue, first, that it is modelled on a transcendental argument which is Kantian in origin and, second that, to the extent that Collingwood’s doctrine of absolute presuppositions is Kantian in inspiration, it belongs to the tradition of normative rather than naturalised epistemology.