Kant's appeal to the fact of reason in the Critique of Practical Reason has been greeted with even less enthusiasm than the ill-fated attempt at a deduction of the moral law in Groundwork III. The general consensus appears to be that even though this deduction failed, it was at least a step in the right direction. Consequently, by abandoning the effort to provide a deduction of the moral law and relying instead on a brute appeal to a putative fact of reason, which in turn is supposed to provide the basis for a deduction of freedom, Kant in effect reverted to a precritical dogmatism of practical reason. As Schopenhauer puts it, in commenting on the acceptance of this conception by Kant's followers:

In the present chapter I shall argue that far from being a reversion to a discredited standpoint, Kant's turn to the fact of reason marks a genuine advance, indeed, that given the basic principles of Kant's philosophy, it offers the best available strategy for authenticating the moral law and establishing the reality of transcendental freedom. I shall also argue that given these principles, this strategy is reasonably successful on both counts, although it can hardly be expected to convince someone who rejects either the account of morality as based on a categorical imperative or transcendental idealism.