In relation to the present problem, therefore, the regulative principle of reason is that everything in the sensuous world possesses an empirically conditioned existence—that no property of the sensuous world possesses unconditioned necessity—that we are bound to expect, and, so far as is possible, to seek for the empirical condition of every member in the series of conditions—and that there is no sufficient reason to justify us in deducing any existence from a condition which lies out of and beyond the empirical series, or in regarding any existence as independent and self-subsistent; although this should not prevent us from recognizing the possibility of the whole series being based upon a being which is intelligible, and for this reason free from all empirical conditions.
But it has been far from my intention, in these remarks, to prove the existence of this unconditioned and necessary being, or even to evidence the possibility of a purely intelligible condition of the existence of all sensuous phenomena. As bounds were set to reason, to prevent it from leaving the guiding thread of empirical conditions and losing itself in transcendent theories which are incapable of concrete presentation; so it was my purpose, on the other hand, to set bounds to the law of the purely empirical understanding, and to protest against any attempts on its part at deciding on the possibility of things, or declaring the existence of the intelligible to be impossible, merely on the ground that it is not available for the explanation and exposition of phenomena. It has been shown, at the same time, that the contingency of all the phenomena of nature and their empirical conditions is quite consistent with the arbitrary hypothesis of a necessary, although purely intelligible condition, that no real contradiction exists between them and that, consequently, both may be true. The existence of such an absolutely necessary being may be impossible; but this can never be demonstrated from the universal contingency and dependence of sensuous phenomena, nor from the principle which forbids us to discontinue the series at some member of it, or to seek for its cause in some sphere of existence beyond the world of nature. Reason goes its way in the empirical world, and follows, too, its peculiar path in the sphere of the transcendental.
The sensuous world contains nothing but phenomena, which are mere representations, and always sensuously conditioned; things in themselves are not, and cannot be, objects to us. It is not to be wondered at, therefore, that we are not justified in leaping from some member of an empirical series beyond the world of sense, as if empirical representations were things in themselves, existing apart from their transcendental ground in the human mind, and the cause of whose existence may be sought out of the empirical series. This would certainly be the case with contingent things; but it cannot be with mere representations of things, the contingency of which is itself merely a phenomenon and can relate to no other regress than that which determines phenomena, that is, the empirical. But to cogitate an intelligible ground of phenomena, as free, moreover, from the contingency of the latter, conflicts neither with the unlimited nature of the empirical regress, nor with the complete contingency of phenomena. And the demonstration of this was the only thing necessary for the solution of this apparent antinomy. For if the condition of every conditioned—as regards its existence—is sensuous, and for this reason a part of the same series, it must be itself conditioned, as was shown in the antithesis of the fourth antinomy. The embarrassments into which a reason, which postulates the unconditioned, necessarily falls, must, therefore, continue to exist; or the unconditioned must be placed in the sphere of the intelligible. In this way, its necessity does not require, nor does it even permit, the presence of an empirical condition: and it is, consequently, unconditionally necessary.
The empirical employment of reason is not affected by the assumption of a purely intelligible being; it continues its operations on the principle of the contingency of all phenomena, proceeding from empirical conditions to still higher and higher conditions, themselves empirical. Just as little does this regulative principle exclude the assumption of an intelligible cause, when the question regards merely the pure employment of reason—in relation to ends or aims. For, in this case, an intelligible cause signifies merely the transcendental and to us unknown ground of the possibility of sensuous phenomena, and its existence, necessary and independent of all sensuous conditions, is not inconsistent with the contingency of phenomena, or with the unlimited possibility of regress which exists in the series of empirical conditions.
Concluding Remarks on the Antinomy of Pure Reason.
So long as the object of our rational conceptions is the totality of conditions in the world of phenomena, and the satisfaction, from this source, of the requirements of reason, so long are our ideas transcendental and cosmological. But when we set the unconditioned—which is the aim of all our inquiries—in a sphere which lies out of the world of sense and possible experience, our ideas become transcendent. They are then not merely serviceable towards the completion of the exercise of reason (which remains an idea, never executed, but always to be pursued); they detach themselves completely from experience and construct for themselves objects, the material of which has not been presented by experience, and the objective reality of which is not based upon the completion of the empirical series, but upon pure à priori conceptions. The intelligible object of these transcendent ideas may be conceded, as a transcendental object. But we cannot cogitate it as a thing determinable by certain distinct predicates relating to its internal nature, for it has no connection with empirical conceptions; nor are we justified in affirming the existence of any such object. It is, consequently, a mere product of the mind alone. Of all the cosmological ideas, however, it is that occasioning the fourth antinomy which compels us to venture upon this step. For the existence of phenomena, always conditioned and never self-subsistent, requires us to look for an object different from phenomena—an intelligible object, with which all contingency must cease. But, as we have allowed ourselves to assume the existence of a self-subsistent reality out of the field of experience, and are therefore obliged to regard phenomena as merely a contingent mode of representing intelligible objects employed by beings which are themselves intelligences—no other course remains for us than to follow analogy and employ the same mode in forming some conception of intelligible things, of which we have not the least knowledge, which nature taught us to use in the formation of empirical conceptions. Experience made us acquainted with the contingent. But we are at present engaged in the discussion of things which are not objects of experience; and must, therefore, deduce our knowledge of them from that which is necessary absolutely and in itself, that is, from pure conceptions. Hence the first step which we take out of the world of sense obliges us to begin our system of new cognition with the investigation of a necessary being, and to deduce from our conceptions of it all our conceptions of intelligible things. This we propose to attempt in the following chapter.
Chapter III. The Ideal of Pure Reason
Section I. Of the Ideal in General
We have seen that pure conceptions do not present objects to the mind, except under sensuous conditions; because the conditions of objective reality do not exist in these conceptions, which contain, in fact, nothing but the mere form of thought. They may, however, when applied to phenomena, be presented in concreto; for it is phenomena that present to them the materials for the formation of empirical conceptions, which are nothing more than concrete forms of the conceptions of the understanding. But ideas are still further removed from objective reality than categories; for no phenomenon can ever present them to the human mind in concreto. They contain a certain perfection, attainable by no possible empirical cognition; and they give to reason a systematic unity, to which the unity of experience attempts to approximate, but can never completely attain.
But still further removed than the idea from objective reality is the Ideal, by which term I understand the idea, not in concreto, but in individuo—as an individual thing, determinable or determined by the idea alone. The idea of humanity in its complete perfection supposes