The difference between the method of metaphysics and the method of mathematics was an issue of central concern for Kant in both the Pre-Critical and Critical periods. I will argue that when Kant speaks of the ‘philosophical method’ in the Doctrine of Method in the Critique of Pure Reason (CPR), he frequently has in mind not his own methodology but rather the method of conceptual analysis associated with rationalism. The particular target is Moses Mendelssohn’s picture of analysis contained in his submission for the 1763 Prize Essay competition. By the time of the first Critique, I argue, Kant wants to maintain his own longstanding commitment to the distinctness of the methods of metaphysics and mathematics. However, Kant wants to use this same analysis of the source of the distinction to diagnose the origins of the dogmatism that is engendered by the method of the rationalists.