Kant's chief object, after all, was to discredit the discursive understanding as an instrument of ultimate truth, the same intelligence which the sceptics, faith-philosophers, intuitionists, and mystics, before and after his day, distrusted and rejected. He destroyed its knowledge to make room for a rational faith in a supersensible world. The scientific study of outer and inner nature, as conceived by him, will not help us in our attempt to get to the bottom of things; a metaphysic erected upon empirical foundations is built on sand. If there were not another, deeper source of truth in the practical reason, we should not only know nothing of freedom and the ideal world, but be unable to free ourselves from the mechanism of nature. It is moral truth that both sets us free and demonstrates our freedom. The effort of reason to think itself into the heart of reality by means of the discursive intellect is doomed to failure and must be abandoned.
Und was sie deinem Geist nicht offenbaren mag,
Das zwingst du ihr nicht ab mit Hebeln und mit Schrauben.
But Kant does not seek in sentimentalism or mysticism the solution of the world-riddle;—he had contempt for all Schuärmerei of this sort, for Schwärmerei ins Überschwängliche,—he is unwilling to leave the safe footing of reason and would climb into the supersensible by rational steps from rational moral principles.
And yet, in spite of all his rationalism, his appeal is, nevertheless, an appeal to the heart; faith in the moral ideal saves us from agnosticism, materialism, and determinism; we know because we believe in the moral law. It is true, as Schelling says, the Critique of Pure Reason did not refute dogmatism, but dismissed its case from the tribunal of theoretical reason. The discursive understanding, as understood by Kant, is helpless in metaphysics, involving itself in hopeless antinomies; unless philosophy can discover other methods and sources of knowledge than those employed in mathematical physics, it cannot shake off the incubus of a block-universe. That is what troubled both Jacobi and Kant, compelling the former to seek refuge in feeling, the latter in a rational moral faith. Spinozism had become popular in Germany during the latter part of the eighteenth century and appealed to many thinkers as the most consistent dogmatic
