Since my act, through affection, delights me—
with the following decision:
The friends whom thou lov’st, thou must first seek to scorn,
For to no other way can I guide thee:
’Tis alone with disgust thou canst rightly perform
The acts to which duty would lead thee.
(2.) The Dialectic.—The pure reason has always its dialectics, since it belongs to the nature of the reason to demand the unconditioned for the given conditioned. Hence also the practical reason seeks an unconditioned highest good for that conditioned good after which man strives. What is this highest good? If we understand by the highest good the fundamental condition of all other goods, then it is virtue. But virtue is not the perfect good, since the finite reason as sensitive stands in need also of happiness. Hence the highest good is only perfect when the highest happiness is joined to the highest virtue. The question now arises: what is the relation of these two elements of the highest good to each other? Are they analytically or synthetically connected together? The former would be affirmed by most of the ancients, especially by the Greek moral philosophers. We might allow with the Stoics, that happiness is contained as an accidental element in virtue, or, with the Epicureans, that virtue is contained as an accidental element in happiness. The Stoics said: to be conscious of one’s virtue is happiness; the Epicureans said: to be conscious of the maxims leading one to happiness is virtue. But, says Kant, an analytic connection between these two conceptions is not possible, since they are wholly different in kind. Consequently there can be between them only a synthetic unity, and this unity more closely scanned is seen to be a causal one, so that the one element is cause, and the other effect. Such a relation must be regarded as its highest good by the practical reason, whose thesis must therefore be: virtue and happiness must be bound together in a correspondent degree as cause and effect. But this thesis is all thwarted by the actual fact. Neither of the two is the direct cause of the other. Neither is the striving after happiness a moving spring to virtue, nor is virtue the efficient cause of happiness. Hence the antithesis: virtue and happiness do not necessarily correspond, and are not universally connected as cause and effect. The critical solution of this antinomy Kant finds in distinguishing between the sensible and the intelligible world. In the world of sense, virtue and happiness do not, it is true, correspond; but the reason as noumenon is also a citizen of a supersensible world, where the counter-strife between virtue and happiness has no place. In this supersensible world virtue is always adequate to happiness, and when man passes over into this he may look for the actualization of the highest good. But the highest good has, as already remarked, two elements, (1) highest virtue, (2) highest happiness. The actualization demanded for the first of these elements postulates the immortality of the soul, and for the second, the existence of God.
(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 us free space to act through reverence for the moral law.