always be given really in concreto, although only partially, nay, it is the indispensable condition of all practical employment of reason. The practice or execution of the idea is always limited and defective, but nevertheless within indeterminable boundaries, consequently always under the influence of the conception of an absolute perfection. And thus the practical idea is always in the highest degree fruitful, and in relation to real actions indispensably necessary. In the idea, pure reason possesses even causality and the power of producing that which its conception contains. Hence we cannot say of wisdom, in a disparaging way, “it is only an idea.” For, for the very reason that it is the idea of the necessary unity of all possible aims, it must be for all practical exertions and endeavours the primitive condition and rule — a rule which, if not constitutive, is at least limitative.
Now, although we must say of the transcendental conceptions of reason, “they are only ideas,” we must not, on this account, look upon them as superfluous and nugatory. For, although no object can be determined by them, they can be of great utility, unobserved and at the basis of the edifice of the understanding, as the canon for its extended and self-consistent exercise — a canon which, indeed, does not enable it to cognize more in an object than it would cognize by the help of its own conceptions, but which guides it more securely in its cognition. Not to mention that they perhaps render possible a transition from our conceptions of nature and the non-ego to the practical conceptions, and thus produce for even ethical ideas keeping, so to speak, and connection with the speculative cognitions of reason. The explication of all this must be looked for in the sequel.
But setting aside, in conformity with our original purpose, the consideration of the practical ideas, we proceed to contemplate reason in its speculative use alone, nay, in a still more restricted sphere, to wit, in the transcendental use; and here must strike into the same path which we followed in our deduction of the categories. That is to say, we shall consider the logical form of the cognition of reason, that we may see whether reason may not be thereby a source of conceptions which enables us to regard objects in themselves as determined synthetically a priori, in relation to one or other of the functions of reason.
Reason, considered as the faculty of a certain logical form of cognition, is the faculty of conclusion, that is, of mediate judgement — by means of the subsumption of the condition of a possible judgement under the condition of a given judgement. The given judgement is the general rule (major). The subsumption of the condition of another possible judgement under the condition of the rule is the minor. The actual judgement, which enounces the assertion of the rule in the subsumed case, is the conclusion (conclusio). The rule predicates something generally under a certain condition. The condition of the rule is satisfied in some particular case. It follows that what was valid in general under that condition must also be considered as valid in the particular case which satisfies this condition. It is very plain that reason attains to a cognition, by means of acts of the understanding which constitute a series of conditions. When I arrive at the proposition, “All bodies are changeable,” by beginning with the more remote cognition (in which the conception of body does not appear, but which nevertheless contains the condition of that conception), “All compound is changeable,” by proceeding from this to a less remote cognition, which stands under the condition of the former, “Bodies are compound,” and hence to a third, which at length connects for me the remote cognition (changeable) with the one before me, “Consequently, bodies are changeable”— I have arrived at a cognition (conclusion) through a series of conditions (premisses). Now every series, whose exponent (of the categorical or hypothetical judgement) is given, can be continued; consequently the same procedure of reason conducts us to the ratiocinatio polysyllogistica, which is a series of syllogisms, that can be continued either on the side of the conditions (per prosyllogismos) or of the conditioned (per episyllogismos) to an indefinite extent.
But we very soon perceive that the chain or series of prosyllogisms, that is, of deduced cognitions on the side of the grounds or conditions of a given cognition, in other words, the ascending series of syllogisms must have a very different relation to the faculty of reason from that of the descending series, that is, the progressive procedure of reason on the side of the conditioned by means of episyllogisms. For, as in the former case the cognition (conclusio) is given only as conditioned, reason can attain to this cognition only under the presupposition that all the members of the series on the side of the conditions are given (totality in the series of premisses), because only under this supposition is the judgement we may be considering possible a priori; while on the side of the conditioned or the inferences, only an incomplete and becoming, and not a presupposed or given series, consequently only a potential progression, is cogitated. Hence, when a cognition is contemplated as conditioned, reason is compelled to consider the series of conditions in an ascending line as completed and given in their totality. But if the very same condition is considered at the same time as the condition of other cognitions, which together constitute a series of inferences or consequences in a descending line, reason may preserve a perfect indifference, as to how far this progression may extend a parte posteriori, and whether the totality of this series is possible, because it stands in no need of such a series for the purpose of arriving at the conclusion before it, inasmuch as this conclusion is sufficiently guaranteed and determined on grounds a parte priori. It may be the case, that upon the side of the conditions the series of premisses has a first or highest condition, or it may not possess this, and so be a parte priori unlimited; but it must, nevertheless, contain totality of conditions, even admitting that we never could succeed in completely apprehending it; and the whole series must be unconditionally true, if the conditioned, which is considered as an inference resulting from it, is to be held as true. This is a requirement of reason, which announces its cognition as determined a priori and as necessary, either in itself — and in this case it needs no grounds to rest upon — or, if it is deduced, as a member of a series of grounds, which is itself unconditionally true.
Section III. System of Transcendental Ideas.
We are not at present engaged with a logical dialectic, which makes complete abstraction of the content of cognition and aims only at unveiling the illusory appearance in the form of syllogisms. Our subject is transcendental dialectic, which must contain, completely a priori, the origin of certain cognitions drawn from pure reason, and the origin of certain deduced conceptions, the object of which cannot be given empirically and which therefore lie beyond the sphere of the faculty of understanding. We have observed, from the natural relation which the transcendental use of our cognition, in syllogisms as well as in judgements, must have to the logical, that there are three kinds of dialectical arguments, corresponding to the three modes of conclusion, by which reason attains to cognitions on principles; and that in all it is the business of reason to ascend from the conditioned synthesis, beyond which the understanding never proceeds, to the unconditioned which the understanding never can reach.
Now the most general relations which can exist in our representations are: 1st, the relation to the subject; 2nd, the relation to objects, either as phenomena, or as objects of thought in general. If we connect this subdivision with the main division, all the relations of our representations, of which we can form either a conception or an idea, are threefold: 1. The relation to the subject; 2. The relation to the manifold of the object as a phenomenon; 3. The relation to all things in general.
Now all pure conceptions have to do in general with the synthetical unity of representations; conceptions of pure reason (transcendental ideas), on the other hand, with the unconditional synthetical unity of all conditions. It follows that all transcendental ideas arrange themselves in three classes, the first of which contains the absolute (unconditioned) unity of the thinking subject, the second the absolute unity of the series of the conditions of a phenomenon, the third the absolute unity of the condition of all objects of thought in general.
The thinking subject is the object-matter of Psychology; the sum total of all phenomena (the world) is the object-matter of Cosmology; and the thing which contains the highest
