This paper challenges the claim – found in the work of scholars such as Robert Pippin, Sebastian Rödl and Dennis Schulting – that for Kant the objective validity of judgments is fully determined by the unity of apperception. It argues that Kant uses “objective validity” not merely to indicate objective reference but also, in key contexts, to denote truth or correctness. Drawing on Kant’s distinction between Denken (thinking) and Erkennen (knowing), and on his analysis of error and illusion, the paper defends the view that not all judgments in which the categories are instantiated are objectively valid. Properly understood, objective validity presupposes not only apperceptive form but also relation to intuition and the possibility of empirical verification.