(_a._) To the highest good belongs in the first place perfect virtue or holiness. But no creature of sense can be holy: reason united to sense can only approximate holiness as an ideal in an endless progression. But such an endless progress is only possible in an endless continuance of personal existence. If, therefore, the highest good shall ever be actualized, the immortality of the soul must be presupposed. (_b._) To the highest good belongs, in the second place, perfect happiness. Happiness is that condition of a rational creature in the world, to whom every thing goes according to his desire and will. This can only occur when all nature is in accord with his ends. But this is not the case; as acting beings we are not the cause of nature, and there is not the slightest ground in the moral law for connecting morality and happiness. Notwithstanding this, we _ought_ to endeavor to secure the highest good. It must therefore be possible. There is thus postulated the necessary connection of these two elements, _i. e._ the existence of a cause of nature distinct from nature, and which contains the ground of this connection. There must be a being as the common cause of the natural and moral world, a being who knows our characters of intelligence, and who, according to this intelligence imparts to us happiness. Such a being is God. Thus from the practical reason there issue the ideas of immortality and of God, as we have already seen to be the case with the idea of freedom. The reality of the idea of freedom is derived from the possibility of a moral law; that of the idea of immortality is borrowed from the possibility of a perfect virtue; that of the idea of a God follows from the necessary demand of a perfect happiness. These three ideas, therefore, which the speculative reason has treated as problems that could not be solved, gain a firm basis in the province of the practical reason. Still they are not yet theoretical dogmas, but as Kant calls them practical postulates, necessary premises of moral action. My theoretical knowledge is not enlarged by them: I only know now that there are objects corresponding to these ideas, but of these objects I can know no more. Of God, for instance, we possess and know no more than this very conception; and if we should attempt to establish the theory of the supersensible grounded upon such categories, this would be to make theology like a magic lantern, with its phantasmagorical representations. Yet has the practical reason acquired for us a certainty respecting the objective reality of these ideas, which the theoretical reason had been obliged to leave undecided, and in this respect the practical reason has the primacy. This relation of the two faculties of knowledge is wisely established in relation to the destiny of men. Since the ideas of God and immortality are theoretically obscure to us, they do not defile our moral motives by fear and hope, but leave