The peculiar problems of metaphysics lie outside the province of philosophical knowledge. Such is the negative part of the Kantian philosophy; its positive complement is found in the “_Critick of the Practical Reason_.” While the mind as theoretical and cognitive is wholly conditioned, and ruled by the objective and sensible world, and thus knowledge is only possible through intuition, yet as practical does it go wholly beyond the given (the sense impulse), and is determined only through the categorical imperative, and the moral law, which is itself, and is therefore free and autonomic; the ends which it pursues are those which itself, as moral spirit, places before itself; objects are no more its masters and lawgivers, to which it must yield if it would know the truth, but its servants, which it may use for its own ends in actualizing its moral law. While the theoretical mind is united to a world of sense and phenomena, a world obedient to necessary laws, the practical mind, by virtue of the freedom essential to it, by virtue of its direction towards an absolute aim, belongs to a purely intelligible and supersensible world. This is the practical idealism of Kant, from which he derives the three practical postulates of the immortality of the soul, moral freedom, and the being of a God, which, as theoretical truths, had been before denied. With this brief sketch for our guidance, let us now pass on to a more extended exposition of the Kantian Philosophy. SECTION XXXVIII. KANT.