ractical faith.

* * * * *

There are three original and pregnant pairs of thoughts which cause Kant's
name to shine in the philosophical sky as a star of the first magnitude:
the demand for a critique of knowledge and the proof of _a priori_ forms
of knowledge; the moral autonomy and the categorical imperative; the
regulative validity of the Ideas of reason and the practical knowledge of
the transcendent world. No philosophical theory, no scientific hypothesis
can henceforth avoid the duty of examining the value and legitimacy of its
conclusions, as to whether they keep within the limits of the competency of
human reason; whether Kant's determination of the origin and the limits of
knowledge may count on continued favor or not, the fundamental critical
idea, that reflection upon the nature and range of our cognitive faculty is
indispensable, retains its validity for all cases and makes an end of all
philosophizing at random.[1] No ethical system will with impunity pass by
the autonomous legislation of reason and the unconditional imperative (the
admonition of conscience translated into conceptual language): the nature
and worth of moral will will be everywhere sought in vain if they are not
recognized where Kant has found them--in the unselfish disposition, in that
maxim which is fitted to become a general law for all rational beings.
The doctrine of the Ideas, finally, reveals to us, beyond the daylight of
phenomenal knowledge, the starlit landscape of another mode of looking at
things,[2] in which satisfaction is afforded for the hitherto unmet wishes
of the heart and demands of the reason.

[Footnote 1: "_Reason_ consists just in this, that we are able to give
account of all our concepts, opinions, and assertions, either on objective
or subjective grounds."]

[Footnote 2: Those who regard all future metaphysics as refuted by the
Critique of Reason are to be referred to the positive side of the Kantian
doctrine of Ideas. Kant admits that the mechanical explanation does not
satisfy reason, and that, besides it, a judgment according to Ideas is
legitimate. When, therefore, the speculation of the constructive school
gives an ideal interpretation of the world, it may be regarded as an
extended application of "regulative principles," which exceeds its
authority only when it professes to be "objective knowledge."]

The effect of the three _Critiques_ upon the public was very varied. The
f