Kant intended the Inauguraldissertation (1770) as a propaedeutic to a future metaphysics with the help of a critique of metaphysical prejudice. Kant, already then, is committed to the spirit of criticism by questioning which faculty a cognition belongs to. The distinction between sensibility and understanding, and the doctrine of space and time, reconfigure the notion of empirical knowledge, which was no longer deemed confused per se and only gradually differentiated from clear and distinct rational knowledge, as rationalism had erroneously taught. Yet, determining the sensibility’s subjectivity delineates what is to be kept away from scientific metaphysics by the critique of metaphysical prejudice. Despite the elevation of sensibility, a dogmatic asymmetry between a lower (sensibility) and upper faculty of knowledge (understanding/reason) remains. The objectivity of the real use of reason goes hand in hand with the epistemic hubris that the ideas of pure reason could be recognised symbolically (Lambert’s symbolische Erkenntnis) if only the laws of sensibility were not falsely involved in this cognition as false principles (Meier’s unechte Gründe).