41* KANT. that man, as the subject of morality, must be held to be the final aim of the world, for it is only in regard to a moral being that no further inquiry can be raised as to the purpose of its existence. It also repeats the moral argument for the existence of a supreme reason, thus supplementing physico-theology, which is inadequate to the demonstration of one absolutely perfect Deity ; so that the third Critique, like the two preceding, concludes with the Idea of God as an object of practical 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 knowl- edge ; the moral autonomy and the categorical imperative ; the regulative validity of the Ideas of reason and the prac- tical knowledge of the transcendent world. No philosoph- ical theory, no scientific hypothesis can henceforth avoid the duty of examining the value and legitimacy of its con- clusions, as to whether they keep within the limits of the competency of human reason ; whether Kant's determina- tion 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.* No ethical sys- tem will with impunity pass by the autonomous legislation of reason and the unconditional imperative (the admo- nition 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 — m 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, f in which
- " 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."
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.
