In a passage in both editions of the Critique of Pure Reason, Kant describes what he wants to accomplish there as a ‘doctrine of method’ (A82–3/B108–9). In the B-Preface, he adds that the Critique ‘is a treatise on the method’ (Bxxii). In this chapter, I argue that the best way to understand these claims is to see them as an indication that the Critique is the doctrine of method of metaphysics. I start by clarifying what a doctrine of method is for Kant and distinguish between the doctrine of method of general logic and the doctrines of method of particular sciences. In a second step, I argue that the Transcendental Doctrine of Method is the particular doctrine of method of metaphysics. Furthermore, I explain how this is compatible with regarding the whole Critique as the doctrine of method of metaphysics. Since cognitions belonging to a science must already be established in order for a doctrine of method to perform its task, the Transcendental Doctrine of Method requires that at least some doctrinal parts of metaphysics be established in the Transcendental Doctrine of Elements. I argue that this has important consequences for how we should depict the relationship between the critique of pure reason and transcendental philosophy.