In the A-preface of the Critique of Pure Reason, Kant kindly warns his readers to pay special attention to the chapter on the “Deduction of the Pure Concepts of the Understanding.” Looking to mitigate the reader's effort, Kant goes on to explain the chapter's methodology, suggesting that the inquiry will have “two sides.” One side deals with the “objective validity” of the pure categories of the understanding; he calls this the “objective deduction.” The other deals with the powers of cognition (...) on which the understanding rests; he calls this the “subjective deduction.” Having gone to such great lengths to outline his method ahead of time, it comes as no small surprise that the actual chapter offers no clear indication of where the two deductions are located. In this essay, I attempt to solve this puzzle. On the way, I engage with both traditional and recent interpretations of the subjective deduction, arguing that they fail—in one way or another—to satisfy the criteria that Kant develops in the preface. (shrink)