THE TRANSCENDENTAL DEDUCTION OF THE HIGHEST GOOD IN THE CRITIQUE OF PRACTICAL REASON AND THE BOUNDARY OF TRANSCENDE NTAL CRITIQUE

The debate on Kant's conception of the highest good has long been focused on the alternative between secular and religious readings. Bracketing this issue, in this essay I look at Kant's theory of the highest good in the second Critique as a specimen of transcendental critique. Indeed, Kant frames the idea of the highest good as a form of a priori practical synthesis and claims that its possibility has to be clarified by means of a transcendental deduction. Reconstructing the transcendental deduction of the highest good in the Critique of Practical Reason allows us to appraise the boundary encountered by transcendental critique when it tries to explain the possibility of an unconditioned practical synthesis a priori. I proceed in three steps. In 2, I consider Kant's remarks concerning the impossibility of a deduction of the moral law in the second Critique. In 3, I turn to the account of the highest good and show why, in the light of these remarks, Kant believes that a deduction can be given in this case. In 4, I examine the peculiar subjective character of the conclusion of Kant's argument and claim that it reveals the boundary that reason encounters when it tries to clarify the possibility of an unconditioned practical synthesis a priori in a transcendental manner.