But this systematic unity of ends in this world of intelligences—which, as mere nature, is only a world of sense, but, as a system of freedom of volition, may be termed an intelligible, that is, moral world (regnum gratiae)—leads inevitably also to the teleological unity of all things which constitute this great whole, according to universal natural laws—just as the unity of the former is according to universal and necessary moral laws—and unites the practical with the speculative reason. The world must be represented as having originated from an idea, if it is to harmonize with that use of reason without which we cannot even consider ourselves as worthy of reason—namely, the moral use, which rests entirely on the idea of the supreme good. Hence the investigation of nature receives a teleological direction, and becomes, in its widest extension, physico-theology. But this, taking its rise in moral order as a unity founded on the essence of freedom, and not accidentally instituted by external commands, establishes the teleological view of nature on grounds which must be inseparably connected with the internal possibility of things. This gives rise to a transcendental theology, which takes the ideal of the highest ontological perfection as a principle of systematic unity; and this principle connects all things according to universal and necessary natural laws, because all things have their origin in the absolute necessity of the one only Primal Being.
What use can we make of our understanding, even in respect of experience, if we do not propose ends to ourselves? But the highest ends are those of morality, and it is only pure reason that can give us the knowledge of these. Though supplied with these, and putting ourselves under their guidance, we can make no teleological use of the knowledge of nature, as regards cognition, unless nature itself has established teleological unity. For without this unity we should not even possess reason, because we should have no school for reason, and no cultivation through objects which afford the materials for its conceptions. But teleological unity is a necessary unity, and founded on the essence of the individual will itself. Hence this will, which is the condition of the application of this unity in concreto, must be so likewise. In this way the transcendental enlargement of our rational cognition would be, not the cause, but merely the effect of the practical teleology which pure reason imposes upon us.
Hence, also, we find in the history of human reason that, before the moral conceptions were sufficiently purified and determined, and before men had attained to a perception of the systematic unity of ends according to these conceptions and from necessary principles, the knowledge of nature, and even a considerable amount of intellectual culture in many other sciences, could produce only rude and vague conceptions of the Deity, sometimes even admitting of an astonishing indifference with regard to this question altogether. But the more enlarged treatment of moral ideas, which was rendered necessary by the extreme pure moral law of our religion, awakened the interest, and thereby quickened the perceptions of reason in relation to this object. In this way, and without the help either of an extended acquaintance with nature, or of a reliable transcendental insight (for these have been wanting in all ages), a conception of the Divine Being was arrived at, which we now hold to be the correct one, not because speculative reason convinces us of its correctness, but because it accords with the moral principles of reason. Thus it is to pure reason, but only in its practical use, that we must ascribe the merit of having connected with our highest interest a cognition, of which mere speculation was able only to form a conjecture, but the validity of which it was unable to establish—and of having thereby rendered it, not indeed a demonstrated dogma, but a hypothesis absolutely necessary to the essential ends of reason.
But if practical reason has reached this elevation, and has attained to the conception of a sole Primal Being as the supreme good, it must not, therefore, imagine that it has transcended the empirical conditions of its application, and risen to the immediate cognition of new objects; it must not presume to start from the conception which it has gained, and to deduce from it the moral laws themselves. For it was these very laws, the internal practical necessity of which led us to the hypothesis of an independent cause, or of a wise ruler of the universe, who should give them effect. Hence we are not entitled to regard them as accidental and derived from the mere will of the ruler, especially as we have no conception of such a will, except as formed in accordance with these laws. So far, then, as practical reason has the right to conduct us, we shall not look upon actions as binding on us, because they are the commands of God, but we shall regard them as divine commands, because we are internally bound by them. We shall study freedom under the teleological unity which accords with principles of reason; we shall look upon ourselves as acting in conformity with the divine will only in so far as we hold sacred the moral law which reason teaches us from the nature of actions themselves, and we shall believe that we can obey that will only by promoting the weal of the universe in ourselves and in others. Moral theology is, therefore, only of immanent use. It teaches us to fulfil our destiny here in the world, by placing ourselves in harmony with the general system of ends, and warns us against the fanaticism, nay, the crime of depriving reason of its legislative authority in the moral conduct of life, for the purpose of directly connecting this authority with the idea of the Supreme Being. For this would be, not an immanent, but a transcendent use of moral theology, and, like the transcendent use of mere speculation, would inevitably pervert and frustrate the ultimate ends of reason.
Section III. Of Opinion, Knowledge, and Belief
The holding of a thing to be true is a phenomenon in our understanding which may rest on objective grounds, but requires, also, subjective causes in the mind of the person judging. If a judgement is valid for every rational being, then its ground is objectively sufficient, and it is termed a conviction. If, on the other hand, it has its ground in the particular character of the subject, it is termed a persuasion.
Persuasion is a mere illusion, the ground of the judgement, which lies solely in the subject, being regarded as objective. Hence a judgement of this kind has only private validity—is only valid for the individual who judges, and the holding of a thing to be true in this way cannot be communicated. But truth depends upon agreement with the object, and consequently the judgements of all understandings, if true, must be in agreement with each other (consentientia uni tertio consentiunt inter se). Conviction may, therefore, be distinguished, from an external point of view, from persuasion, by the possibility of communicating it and by showing its validity for the reason of every man; for in this case the presumption, at least, arises that the agreement of all judgements with each other, in spite of the different characters of individuals, rests upon the common ground of the agreement of each with the object, and thus the correctness of the judgement is established.
Persuasion, accordingly, cannot be subjectively distinguished from conviction, that is, so long as the subject views its judgement simply as a phenomenon of its own mind. But if we inquire whether the grounds of our judgement, which are valid for us, produce the same effect on the reason of others as on our own, we have then the means, though only subjective means, not, indeed, of producing conviction, but of detecting the merely private validity of the judgement; in other words, of discovering that there is in it the element of mere persuasion.
If we can, in addition to this, develop the subjective causes of the judgement, which we have taken for its objective grounds, and thus explain the deceptive judgement as a phenomenon in our mind, apart altogether from the objective character of the object, we can then expose the illusion and need be no longer deceived by it, although, if its subjective cause lies in our nature, we cannot hope altogether to escape its influence.
I can only maintain, that is, affirm as necessarily valid for every one, that which produces conviction. Persuasion I may keep for myself, if it is agreeable to me; but I cannot, and ought not, to attempt to impose it as binding upon others.
Holding for true, or the subjective validity of a judgement in relation to conviction (which is, at the same time, objectively valid), has the three following degrees: opinion, belief, and knowledge. Opinion is a consciously insufficient judgement, subjectively as well as objectively. Belief is subjectively sufficient, but is recognized as being objectively insufficient. Knowledge is both subjectively and objectively sufficient. Subjective sufficiency is termed conviction (for myself); objective sufficiency is termed certainty (for all). I need not dwell longer on the explanation of such simple conceptions.
I must never venture to be of opinion, without knowing something, at least, by which my judgement, in itself merely problematical, is
