II.3. The Architectonic of Pure Reason

By an architectonic I understand the art of constructing systems. As systematic unity is what first raises ordinary knowledge to the rank of science, that is, makes a system out of a mere aggregate of knowledge, architectonic is the doctrine of the scientific in our knowledge, and therefore necessarily forms part of the doctrine of method.

In accordance with reason’s legislative prescriptions, our diverse modes of knowledge must not be permitted to be a mere rhapsody, but must form a system. Only so can they further the essential ends of reason. By a system I understand the unity of the manifold modes of knowledge under one idea. This idea is the concept provided by reason—of the form of a whole—in so far as the concept determines a priori not only the scope of its manifold content, but also the positions which the parts occupy relatively to one another. The scientific concept of reason contains, therefore, the end and the form of that whole which is congruent with this requirement. The unity of the end to which all the parts relate and in the idea of which they all stand in relation to one another, makes it possible for us to determine from our knowledge of the other parts whether any part be missing, and to prevent any arbitrary addition, or in respect of its completeness any indeterminateness that does not conform to the limits which are thus determined a priori. The whole is thus an organised unity (articulatio), and not an aggregate (coacervatio). It may grow from within (per intussusceptionem), but not by external addition (per appositionem). It is thus like an animal body, the growth of which is not by the addition of a new member, but by the rendering of each member, without change of proportion, stronger and more effective for its purposes.

The idea requires for its realisation a schema, that is, a constituent manifold and an order of its parts, both of which must be determined a priori from the principle defined by its end. The schema, which is not devised in accordance with an idea, that is, in terms of the ultimate aim of reason, but empirically in accordance with purposes that are contingently occasioned (the number of which cannot be foreseen) yields technical unity; whereas the schema which originates from an idea (in which reason propounds the ends a priori, and does not wait for them to be empirically given) serves as the basis of architectonic unity. Now that which we call science, the schema of which must contain the outline (monogramma) and the division of the whole into parts, in conformity with the idea, that is, a priori, and in so doing must distinguish it with certainty and according to principles from all other wholes, is not formed in technical fashion, in view of the similarity of its manifold constituents or of the contingent use of our knowledge in concreto for all sorts of optional external ends, but in architectonic fashion, in view of the affinity of its parts and of their derivation from a single supreme and inner end, through which the whole is first made possible.

No one attempts to establish a science unless he has an idea upon which to base it. But in the working out of the science the schema, nay even the definition which, at the start, he first gave of the science, is very seldom adequate to his idea. For this idea lies hidden in reason, like a germ in which the parts are still undeveloped and barely recognisable even under microscopic observation. Consequently, since sciences are devised from the point of view of a certain universal interest, we must not explain and determine them according to the description which their founder gives of them, but in conformity with the idea which, out of the natural unity of the parts that we have assembled, we find to be grounded in reason itself. For we shall then find that its founder, and often even his latest successors, are groping for an idea which they have never succeeded in making clear to themselves, and that consequently they have not been in a position to determine the proper content, the articulation (systematic unity), and limits of the science.

It is unfortunate that only after we have spent much time in the collection of materials in somewhat random fashion at the suggestion of an idea lying hidden in our minds, and after we have, indeed, over a long period assembled the materials in a merely technical manner, does it first become possible for us to discern the idea in a clearer light, and to devise a whole architectonically in accordance with the ends of reason. Systems seem to be formed in the manner of lowly organisms, through a generatio aequivoca from the mere confluence of assembled concepts, at first imperfect, and only gradually attaining to completeness, although they one and all have had their schema, as the original germ, in the sheer self-development of reason. Hence, not only is each system articulated in accordance with an idea, but they are one and all organically united in a system of human knowledge, as members of one whole, and so as admitting of an architectonic of all human knowledge, which, at the present time, in view of the great amount of material that has been collected, or which can be obtained from the ruins of ancient systems, is not only possible, but would not indeed be difficult. We shall content ourselves here with the completion of our task, namely, merely to outline the architectonic of all knowledge arising from pure reason; and in doing so we shall begin from the point at which the common root of our faculty of knowledge divides and throws out two stems, one of which is reason. By reason I here understand the whole higher faculty of knowledge, and am therefore contrasting the rational with the empirical.

If I abstract from all the content of knowledge, objectively regarded, then all knowledge, subjectively regarded, is either historical or rational. Historical knowledge is cognitio ex datis; rational knowledge is cognitio ex principiis. However a mode of knowledge may originally be given, it is still, in relation to the individual who possesses it, simply historical, if he knows only so much of it as has been given to him from outside (and this in the form in which it has been given to him), whether through immediate experience or narration, or (as in the case of general knowledge) through instruction. Anyone, therefore, who has learnt (in the strict sense of that term) a system of philosophy, such as that of Wolff, although he may have all its principles, explanations, and proofs, together with the formal divisions of the whole body of doctrine, in his head, and, so to speak, at his fingers’ ends, has no more than a complete historical knowledge of the Wolffian philosophy. He knows and judges only what has been given him. If we dispute a definition, he does not know whence to obtain another. He has formed his mind on another’s, and the imitative faculty is not itself productive. In other words, his knowledge has not in him arisen out of reason, and although, objectively considered, it is indeed knowledge due to reason, it is yet, in its subjective character, merely historical. He has grasped and kept; that is, he has learnt well, and is merely a plaster-cast of a living man. Modes of rational knowledge which are rational objectively (that is, which can have their first origin solely in human reason) can be so entitled subjectively also, only when they have been derived from universal sources of reason, that is, from principles—the sources from which there can also arise criticism, nay, even the rejection of what has been learnt.

All knowledge arising out of reason is derived either from concepts or from the construction of concepts. The former is called philosophical, the latter mathematical. I have already treated of the fundamental difference between these two modes of knowledge in the first chapter [of this Transcendental Doctrine of Method]. Knowledge [as we have just noted] can be objectively philosophical, and yet subjectively historical, as is the case with most novices, and with all those who have never looked beyond their School, and who remain novices all their lives. But it is noteworthy that mathematical knowledge, in its subjective character, and precisely as it has been learned, can also be regarded as knowledge arising out of reason, and that there is therefore in regard to mathematical knowledge no such distinction as we have drawn in the case of philosophical knowledge. This is due to the fact that the sources of knowledge, from which alone the teacher can derive his knowledge, lie nowhere but in the essential and genuine principles of reason, and consequently cannot be acquired by the novice from any other source, and cannot be disputed; and this, in turn, is owing to the fact that the employment of reason is here in concreto only, although likewise a priori, namely, in intuition which is pure, and which precisely on that account is infallible, excluding all illusion and error. Mathematics, therefore, alone of all the sciences (a priori) arising from reason, can be learned; philosophy can never be learned, save only in historical fashion; as regards what concerns reason, we can at most learn to philosophise.

Philosophy is the system of all philosophical knowledge. If we are to understand by it the archetype for the estimation of all attempts at philosophising, and if this archetype is to serve for the estimation of each subjective philosophy, the structure of which is often so diverse and liable to alteration, it must be taken objectively. Thus regarded, philosophy is a mere idea of a possible science which nowhere exists in concreto, but to which, by many different paths, we endeavour to approximate, until the one true path, overgrown by the products of sensibility, has at last been discovered, and the image, hitherto so abortive, has achieved likeness to the archetype, so far as this is granted to [mortal] man. Till then we cannot learn philosophy; for where is it, who is in possession of it, and how shall we recognise it? We can only learn to philosophise, that is, to exercise the talent of reason, in accordance with its universal principles, on certain actually existing attempts at philosophy, always, however, reserving the right of reason to investigate, to confirm, or to reject these principles in their very sources.

Hitherto the concept of philosophy has been a merely scholastic concept—a concept of a system of knowledge which is sought solely in its character as a science, and which has therefore in view only the systematic unity appropriate to science, and consequently no more than the logical perfection of knowledge. But there is likewise another concept of philosophy, a conceptus cosmicus, which has always formed the real basis of the term ‘philosophy’, especially when it has been as it were personified and its archetype represented in the ideal philosopher. On this view, philosophy is the science of the relation of all knowledge to the essential ends of human reason (teleologia rationis humanae), and the philosopher is not an artificer in the field of reason, but himself the lawgiver of human reason. In this sense of the term it would be very vainglorious to entitle oneself a philosopher, and to pretend to have equalled the pattern which exists in the idea alone.

The mathematician, the natural philosopher, and the logician, however successful the two former may have been in their advances in the field of rational knowledge, and the two latter more especially in philosophical knowledge, are yet only artificers in the field of reason. There is a teacher, [conceived] in the ideal, who sets them their tasks, and employs them as instruments, to further the essential ends of human reason. Him alone we must call philosopher; but as he nowhere exists, while the idea of his legislation is to be found in that reason with which every human being is endowed, we shall keep entirely to the latter, determining more precisely what philosophy prescribes as regards systematic unity, in accordance with this cosmical concept from the standpoint of its essential ends.

Essential ends are not as such the highest ends; in view of the demand of reason for complete systematic unity, only one of them can be so described. Essential ends are therefore either the ultimate end or subordinate ends which are necessarily connected with the former as means. The former is no other than the whole vocation of man, and the philosophy which deals with it is entitled moral philosophy. On account of this superiority which moral philosophy has over all other occupations of reason, the ancients in their use of the term ‘philosopher’ always meant, more especially, the moralist, and even at the present day we are led by a certain analogy to entitle anyone a philosopher who appears to exhibit self-control under the guidance of reason, however limited his knowledge may be.

The legislation of human reason (philosophy) has two objects, nature and freedom, and therefore contains not only the law of nature, but also the moral law, presenting them at first in two distinct systems, but ultimately in one single philosophical system. The philosophy of nature deals with all that is, the philosophy of morals with that which ought to be.

All philosophy is either knowledge arising out of pure reason, or knowledge obtained by reason from empirical principles. The former is termed pure, the latter empirical philosophy.

The philosophy of pure reason is either a propaedeutic (preparation), which investigates the faculty of reason in respect of all its pure a priori knowledge, and is entitled criticism, or secondly, it is the system of pure reason, that is, the science which exhibits in systematic connection the whole body (true as well as illusory) of philosophical knowledge arising out of pure reason, and which is entitled metaphysics. The title ‘metaphysics’ may also, however, be given to the whole of pure philosophy, inclusive of criticism, and so as comprehending the investigation of all that can ever be known a priori as well as the exposition of that which constitutes a system of the pure philosophical modes of knowledge of this type—in distinction, therefore, from all empirical and from all mathematical employment of reason.

Metaphysics is divided into that of the speculative and that of the practical employment of pure reason, and is therefore either metaphysics of nature or metaphysics of morals. The former contains all the principles of pure reason that are derived from mere concepts (therefore excluding mathematics), and employed in the theoretical knowledge of all things; the latter, the principles which in a priori fashion determine and make necessary all our actions. Now morality is the only code of laws applying to our actions which can be derived completely a priori from principles. Accordingly, the metaphysics of morals is really pure moral philosophy, with no underlying basis of anthropology or of other empirical conditions. The term ‘metaphysics’, in its strict sense, is commonly reserved for the metaphysics of speculative reason. But as pure moral philosophy really forms part of this special branch of human and philosophical knowledge derived from pure reason, we shall retain for it the title ‘metaphysics’. We are not, however, at present concerned with it, and may therefore leave it aside.

It is of the utmost importance to isolate the various modes of knowledge according as they differ in kind and in origin, and to secure that they be not confounded owing to the fact that usually, in our employment of them, they are combined. What the chemist does in the analysis of substances, and the mathematician in his special disciplines, is in still greater degree incumbent upon the philosopher, that he may be able to determine with certainty the part which belongs to each special kind of knowledge in the diversified employment of the understanding and its special value and influence. Human reason, since it first began to think, or rather to reflect, has never been able to dispense with a metaphysics; but also has never been able to obtain it in a form sufficiently free from all foreign elements. The idea of such a science is as old as speculative human reason; and what rational being does not speculate, either in scholastic or in popular fashion? It must be admitted, however, that the two elements of our knowledge—that which is in our power completely a priori, and that which is obtainable only a posteriori from experience—have never been very clearly distinguished, not even by professional thinkers, and that they have therefore failed to bring about the delimitation of a special kind of knowledge, and thereby the true idea of the science which has preoccupied human reason so long and so greatly. When metaphysics was declared to be the science of the first principles of human knowledge, the intention was not to mark out a quite special kind of knowledge, but only a certain precedence in respect of generality, which was not sufficient to distinguish such knowledge from the empirical. For among empirical principles we can distinguish some that are more general, and so higher in rank than others; but where in such a series of subordinated members—a series in which we do not distinguish what is completely a priori from what is known only a posteriori—are we to draw the line which distinguishes the highest or first members from the lower subordinate members? What should we say, if in the reckoning of time we could distinguish the epochs of the world only by dividing them into the first centuries and those that follow? We should ask: Does the fifth, the tenth century, etc., belong with the first centuries? So in like manner I ask: Does the concept of the extended belong to metaphysics? You answer, Yes. Then, that of body too? Yes. And that of fluid body? You now become perplexed; for at this rate everything will belong to metaphysics. It is evident, therefore, that the mere degree of subordination (of the particular under the general) cannot determine the limits of a science; in the case under consideration, only complete difference of kind and of origin will suffice. But the fundamental idea of metaphysics was obscured on yet another side, owing to its exhibiting, as a priori knowledge, a certain similarity to mathematics. Certainly they are related, in so far as they both have an a priori origin; but when we bear in mind the difference between philosophical and mathematical knowledge, namely, that the one is derived from concepts, whereas in the other we arrive at a priori judgments only through the construction of concepts, we have to recognise a decided difference of kind, which has indeed always been in a manner felt but could never be defined by means of any clear criteria. Thus it has come about that since philosophers failed in the task of developing even the idea of their science, they could have no determinate end or secure guidance in the elaboration of it, and, accordingly, in this arbitrarily conceived enterprise, ignorant as they were of the path to be taken, they have always been at odds with one another as regards the discoveries which each claimed to have made on his own separate path, with the result that their science has been brought into contempt, first among outsiders, and finally even among themselves.

All pure a priori knowledge, owing to the special faculty of knowledge in which alone it can originate, has in itself a peculiar unity; and metaphysics is the philosophy which has as its task the statement of that knowledge in this systematic unity. Its speculative part, which has especially appropriated this name, namely, what we entitle metaphysics of nature, and which considers everything in so far as z is ( (not that which ought to be) by means of a priori concepts, is divided in the following manner.

Metaphysics, in the narrower meaning of the term, consists of transcendental philosophy and physiology of pure reason. The former treats only of the understanding and of reason, in a system of concepts and principles which relate to objects in general but take no account of objects that may be given (Ontologia); the latter treats of nature, that is, of the sum of given objects (whether given to the senses, or, if we will, to some other kind of intuition) and is therefore physiology—although only rationalis. The employment of reason in this rational study of nature is either physical or hyperphysical, or, in more adequate terms, is either immanent or transcendent. The former is concerned with such knowledge of nature as can be applied in experience (in concreto), the latter with that connection of objects of experience which transcends all experience. This transcendent physiology has as its object either an inner connection or an outer connection, both, however, transcending possible experience. As dealing with an inner connection it is the physiology of nature as a whole, that is, the transcendental knowledge of the world; as dealing with an outer connection, it is the physiology of the relation of nature as a whole to a being above nature, that is to say, it is the transcendental knowledge of God.

Immanent physiology, on the other hand, views nature as the sum of all objects of the senses, and therefore just as it is given us, but solely in accordance with a priori conditions, under which alone it can ever be given us. There are only two kinds of such objects. 1. Those of the outer senses, and so their sum, corporeal nature. 2. The object of inner sense, the soul, and in accordance with our fundamental concepts of it, thinking nature. The metaphysics of corporeal nature is entitled physics; and as it must contain only the principles of an a priori knowledge of it, rational physics. The metaphysics of thinking nature is entitled psychology, and on the same ground is to be understood as being only the rational knowledge of it.

The whole system of metaphysics thus consists of four main parts: (1) ontology; (2) rational physiology; (3) rational cosmology; (4) rational theology. The second part, namely, the doctrine of nature as developed by pure reason, contains two divisions, physica rationalis and psychologia rationalis.

The originative idea of a philosophy of pure reason itself prescribes this division, which is therefore architectonic, in accordance with the essential ends of reason, and not merely technical, in accordance with accidentally observed similarities, and so instituted as it were at haphazard. Accordingly the division is also unchangeable and of legislative authority. There are, however, some points which may well seem doubtful, and may weaken our conviction as to the legitimacy of its claims.

First of all, how can I expect to have knowledge a priori (and therefore a metaphysics) of objects in so far as they are given to our senses, that is, given in an a posteriori manner? And how is it possible to know the nature of things and to arrive at a rational physiology according to principles a priori The answer is this: we take nothing more from experience than is required to give us an object of outer or of inner sense. The object of outer sense we obtain through the mere concept of matter (impenetrable, lifeless extension), the object of inner sense through the concept of a thinking being (in the empirical inner representation, ‘I think’). As to the rest, in the whole metaphysical treatment of these objects, we must entirely dispense with all empirical principles which profess to add to these concepts any other more special experience, with a view to our passing further judgments upon the objects.

Secondly, how are we to regard empirical psychology, which has always claimed its place in metaphysics, and from which in our times such great things have been expected for the advancement of metaphysics, the hope of succeeding by a priori methods having been abandoned. I answer that it belongs where the proper (empirical) doctrine of nature belongs, namely, by the side of applied philosophy, the a priori principles of which are contained in pure philosophy; it is therefore so far connected with applied philosophy, though not to be confounded with it. Empirical psychology is thus completely banished from the domain of metaphysics; it is indeed already completely excluded by the very idea of the latter science. In conformity, however, with scholastic usage we must allow it some sort of a place (although as an episode only) in metaphysics, and this from economical motives, because it is not yet so rich as to be able to form a subject of study by itself, and yet is too important to be entirely excluded and forced to settle elsewhere, in a neighbourhood that might well prove much less congenial than that of metaphysics. Though it is but a stranger it has long been accepted as a member of the household, and we allow it to stay for some time longer, until it is in a position to set up an establishment of its own in a complete anthropology, the pendant to the empirical doctrine of nature.

Such, then, in general, is the idea of metaphysics. At first more was expected from metaphysics than could reasonably be demanded, and for some time it diverted itself with pleasant anticipations. But these hopes having proved deceptive, it has now fallen into general disrepute. The argument of our Critique, taken as a whole, must have sufficiently convinced the reader that although metaphysics cannot be the foundation of religion, it must always continue to be a bulwark of it, and that human reason, being by its very nature dialectical, can never dispense with such a science, which curbs it, and by a scientific and completely convincing self-knowledge, prevents the devastations of which a lawless speculative reason would otherwise quite inevitably be guilty in the field of morals as well as in that of religion. We can therefore be sure that however cold or contemptuously critical may be the attitude of those who judge a science not by its nature but by its accidental effects, we shall always return to metaphysics as to a beloved one with whom we have had a quarrel. For here we are concerned with essential ends—ends with which metaphysics must ceaselessly occupy itself, either in striving for genuine insight into them, or in refuting those who profess already to have attained it.

Metaphysics, alike of nature and of morals, and especially that criticism of our adventurous and self-reliant reason which serves as an introduction or propaedeutic to metaphysics, alone properly constitutes what may be entitled philosophy, in the strict sense of the term. Its sole preoccupation is wisdom; and it seeks it by the path of science, which, once it has been trodden, can never be overgrown, and permits of no wandering. Mathematics, natural science, even our empirical knowledge, have a high value as means, for the most part, to contingent ends, but also, in the ultimate outcome, to ends that are necessary and essential to humanity. This latter service, however, they can discharge only as they are aided by a knowledge through reason from pure concepts, which, however we may choose to entitle it, is really nothing but metaphysics.

For the same reason metaphysics is also the full and complete development of human reason. Quite apart from its influence, as science, in connection with certain specific ends, it is an indispensable discipline. For in dealing with reason it treats of those elements and highest maxims which must form the basis of the very possibility of some sciences, and of the use of all. That, as mere speculation, it serves rather to prevent errors than to extend knowledge, does not detract from its value. On the contrary this gives it dignity and authority, through that censorship which secures general order and harmony, and indeed the well-being of the scientific commonwealth, preventing those who labour courageously and fruitfully on its behalf from losing sight of the supreme end, the happiness of all mankind.