Chapter 3. The Architectonic of Pure Reason

What I mean by an architectonic is the art proper to systems. It is systematic unity that first elevates ordinary cognition into a science — that turns a mere aggregate of it into a system — and for this reason the architectonic is the teaching about whatever is scientific in our cognition taken as a whole, so that it belongs of necessity to the doctrine of method.

Where reason holds sway, our cognitions are not permitted to form any rhapsody whatever; they are required instead to make up a system, since only within one can they lend support to reason's essential ends and carry them forward. And by a system I mean the unity of manifold cognitions brought together under one idea. Such an idea is the rational concept of the form of a whole, to the extent that this concept fixes a priori both how far the manifold extends and where the several parts stand in relation to one another . Hence this scientific concept of reason holds within it the end together with the form of that whole which answers to it. Because the end is one — and all the parts refer to it, and, within its idea, to one another as well — it comes about that any part may be found wanting once the others are known, and that no chance addition occurs, nor any indeterminate magnitude of perfection lacking the boundaries fixed for it a priori. The whole is therefore jointed (articulatio) rather than piled up (coacervatio); it may grow from within (per intussusceptionem), though never from without (per appositionem), just as an animal body grows without gaining a single limb, its growth leaving the proportions untouched while rendering each part stronger and fitter for its ends.

To be carried out, the idea stands in need of a schema, that is, of an essential manifoldness and arrangement of the parts, both fixed a priori out of the principle of the end. Where a schema is sketched not from an idea — that is, not from reason's principal end — but empirically, following intentions that happen to turn up (whose sum no one can foresee), it delivers technical unity; where, by contrast, it springs solely in consequence of an idea (reason here assigning the ends a priori rather than waiting on experience for them), it founds architectonic unity. What we name a science can arise not technically — through some resemblance among the manifold, or through a chance employment of cognition in concreto toward any external ends one pleases — but only architectonically, by virtue of the kinship and the descent from one sole supreme and inner end that alone renders the whole possible; and the schema of such a science must set out the contour (monogramma) as well as the partition of the whole into members conformably to the idea, that is, a priori, and must mark it off with certainty and on principles from all the rest.

No one sets out to establish a science unless some idea underlies his effort. Yet as he works it out, the schema — indeed even the definition he offers of his science at the very start — seldom matches his idea; for the idea rests in reason after the fashion of a seed, within which every part still lies tightly folded and so hidden as to be barely discernible even under microscopic scrutiny. On that account, seeing that all sciences are conceived from the vantage of some general interest, one ought to expound and delimit them not by the description their originator supplies of them, but by the idea that one discovers grounded in reason itself, an idea drawn from the natural unity of the parts he has brought together. For it will emerge in that case that the originator, and frequently his latest heirs as well, grope about an idea they have never managed to make plain to themselves, and are therefore unable to pin down the distinctive content, the articulation (systematic unity), and the limits of the science.

It is a sorry thing that only once we have, over a long stretch and at the prompting of an idea concealed within us, gathered up in rhapsodic fashion a mass of pertinent cognitions to serve as building stock — indeed only once we have for lengthy spans of time fitted them together technically — does it at last become possible for us to catch sight of the idea in a brighter light and to lay out a whole architectonically in keeping with the ends of reason. Systems have the look of worms, sprung by a generatio aequivoca from the sheer running-together of amassed concepts — misshapen at first and, with time, brought to completion — even though one and all they held their schema as the original seed within a reason that merely unfolds itself, so that each is not only jointed on its own according to an idea, but the whole set are, beyond that, joined purposefully to one another, standing once more as limbs of one body within a system of human cognition, and thus make room for an architectonic of all human knowledge which, in our own day — when material lies gathered already in such quantity, or may be retrieved from the rubble of old edifices that have caved in — would prove not merely attainable but hardly even difficult. For our part we rest content with finishing the task before us, which is simply to lay out the architectonic of all cognition that issues from pure reason, and we take our start only from that juncture at which the common root of our cognitive power splits and sends up two trunks, one being reason. Here, though, by reason I mean the whole of the higher faculty of cognition, thereby setting the rational over against the empirical.

Should I set aside the entire content of cognition, regarded objectively, then, on the subjective side, all cognition is either historical or rational. Historical cognition amounts to cognitio ex datis, the rational to cognitio ex principiis. However a cognition may first have been supplied, and from whatever quarter, it remains, for whoever holds it, historical, provided he cognizes only to the measure and the amount handed to him from without; and this handing-over may reach him through firsthand experience, through report, or else through instruction (in general cognitions). Thus a man who has genuinely learned a philosophical system — the Wolffian, say — even were he to carry in his head all its principles, its explications and demonstrations, along with the layout of the entire doctrinal structure, and could tick every item off on his fingers, still possesses none but a complete historical cognition of the Wolffian philosophy; he knows and adjudges no more than was consigned to him. Let a definition be contested against him, and he is at a loss where to procure another. He shaped himself upon another's reason, yet the faculty that copies is not the faculty that generates — that is, in him the cognition did not well up out of reason — and although objectively it was indeed a cognition of reason, on the subjective side it stays merely historical. He apprehended well and held fast, that is, he learned, and he is a plaster impression taken from a living man. Cognitions of reason that are so objectively (in that they can, to begin with, well up only from the human being's own reason) are entitled to carry this name subjectively too, but only where they have been drawn from reason's universal wellsprings — the very source from which criticism, and even the repudiation of what was learned, may equally proceed — in short, from principles.

Every cognition of reason is at this point either one derived from concepts or one derived from the construction of concepts; the first we term philosophical, the second mathematical. The inner difference between the two I have already dealt with in the first chapter. A cognition may thus be philosophical objectively and yet historical subjectively, as happens with the majority of pupils and with all who never look past the schoolroom and stay pupils for life. It is curious, all the same, that mathematical cognition, precisely as one has picked it up, can pass subjectively for cognition of reason as well, so that the sort of split found in the philosophical case does not arise for it. The reason lies in this: the springs of cognition on which the teacher alone can draw are situated nowhere but in the essential and authentic principles of reason, and so cannot be fetched by the pupil from any other quarter, nor indeed contested; and this holds because here reason is exercised only in concreto, yet still a priori — namely upon the pure and for that very reason faultless intuition — and thereby shuts out all illusion and error. Among all the rational sciences (a priori), then, mathematics alone can be learned, philosophy never (save historically); where reason itself is concerned, the most one can learn is to philosophize.

The system embracing all philosophical cognition is precisely philosophy. One is bound to take it objectively when one means by it the prototype against which every attempt at philosophizing is to be measured, a prototype serving to appraise each subjective philosophy, whose structures are so often varied and so often shifting. Taken this way, philosophy is a mere idea of a science that might be, nowhere handed to us in concreto, though one strives to draw near it along sundry routes until the sole footpath — badly overgrown by sensibility — comes to light and the hitherto botched copy is made, so far as is granted to human beings, to match the prototype. Until that point no philosophy can be learned; for where does it reside, who has it in hand, and by what marks is it to be known? One can learn only to philosophize — that is, to train reason's talent by having it follow its universal principles across certain attempts already at hand, though always keeping in reserve reason's right to probe those principles at their sources and to uphold or discard them.

Up to that point, however, the concept of philosophy is nothing beyond a scholastic concept, namely of a system of cognition pursued solely as a science, aiming at nothing further than the systematic unity of this knowledge and thus at the logical completeness of cognition. But there is besides a cosmic concept (conceptus cosmicus) that has at all times lain beneath this label, above all whenever one personified it, as it were, and pictured it as a prototype in the ideal of the philosopher. On this understanding, philosophy is the science that treats how all cognition bears on the essential ends of human reason (teleologia rationis humanae), and the philosopher is no craftsman of reason but the lawgiver of human reason. In that sense it would be great presumption to style oneself a philosopher and to lay claim to having matched the prototype, which resides in the idea alone.

The mathematician, the natural scientist, the logician — however splendid the progress the former may make in cognition of reason at large, and the latter above all in philosophical cognition — remain for all that mere craftsmen of reason. There is besides a teacher in the ideal who deploys them all, turning them into tools for advancing the essential ends of human reason. Him alone ought we to call the philosopher; but since he is nowhere to be encountered, while the idea of his lawgiving is encountered everywhere, in every human reason, we shall confine ourselves to the latter and settle more closely what systematic unity philosophy, taken by this cosmic concept,⁷⁴ lays down from the vantage of ends.

Essential ends are not on that account already the highest, of which (once reason attains perfect systematic unity) there can be but one. They are accordingly either the final end or subordinate ends that necessarily attach to it as means. The former is nothing else than the whole vocation of the human being, and the philosophy bearing on it we call morals. Because of this precedence that moral philosophy enjoys over every other pursuit of reason, the ancients too, under the name of philosopher, always meant at once and by preference the moralist; and even now the outward appearance of governing oneself through reason is what leads us, by a kind of analogy, to call a person a philosopher despite the narrowness of his knowledge.

The lawgiving of human reason (philosophy) has, then, two objects, nature and freedom, and so comprises the law of nature no less than the law of morals — housed first in two distinct systems, but in the end within one philosophical system alone. The philosophy of nature reaches to all that is, that of morals only to what ought to be.

All philosophy, though, is either cognition sprung from pure reason or cognition of reason resting on empirical principles. The first we call pure philosophy, the second empirical.

The philosophy of pure reason is now either propaedeutic (a preparatory drill), which examines reason's capacity with regard to all pure cognition a priori and bears the name critique, or, secondly, the system of pure reason (as a science), the entire body of philosophical cognition from pure reason — true and apparent alike — in systematic coherence, bearing the name metaphysics; though this last name may equally be conferred on the whole of pure philosophy, critique included, so as to gather up both the inquiry into everything that can ever be cognized a priori and the exposition of whatever makes up a system of pure philosophical cognitions of this sort, marked off, however, from all empirical and likewise from the mathematical use of reason.

Metaphysics splits into a metaphysics of the speculative and one of the practical use of pure reason, and is thus either a metaphysics of nature or a metaphysics of morals. The former holds all the pure principles of reason drawn from concepts alone (mathematics thereby excluded) that govern the theoretical cognition of all things; the latter holds the principles that fix what is to be done and left undone a priori and render it necessary. Now morality is the sole conformity-to-law of actions that admits of being derived wholly a priori from principles. The metaphysics of morals is therefore, strictly, pure morality, one that rests on no anthropology (no empirical condition) as its foundation. The metaphysics of speculative reason is what one customarily labels metaphysics in the narrower sense; but since pure moral doctrine belongs nonetheless to that special stem of human — indeed philosophical — cognition out of pure reason, we mean to keep that title for it, even while we set it aside here as not pertaining to our purpose just now.

It matters in the highest degree to isolate cognitions that stand apart from others in kind and in origin, and to take careful precaution that they do not merge into a blend with those to which, in use, they are ordinarily tied. What the chemist does in parting substances, and the mathematician in his pure theory of quantity, falls upon the philosopher still more heavily, so that he may pin down with assurance the portion that a distinct species of cognition contributes to the stray use of the understanding, and thereby its peculiar worth and influence. For this reason human reason, ever since it began to think — or rather to reflect — has at no time gone without a metaphysics, and yet has never been able to set it forth cleansed sufficiently of everything alien to it. The idea of a science of this kind runs back as far as speculative human reason itself; and what reason does not speculate, be it in a scholastic or in a popular vein? One must grant, meanwhile, that the separation of the two elements of our cognition — the one sort wholly within our command a priori, the other to be had only a posteriori from experience — stayed exceedingly murky even among thinkers by trade, and could on that account never accomplish the bounding-off of a distinct species of cognition, and hence never the genuine idea of a science that has so long and so keenly engaged human reason. Were one to say that metaphysics is that science which handles the first principles of human cognition, one would thereby single out not a wholly distinct species but merely a rank as regards generality, so that on this footing it could not be told apart in any recognizable way from the empirical; for among empirical principles too some are broader and hence loftier than others; and along the sequence of such a subordination (given that one does not part what is wholly a priori from what is cognized only a posteriori): at what point is the cut to be made that would sever the first portion and the topmost members from the last and the ones ranked beneath? What would be said if chronology could mark off the epochs of the world only in this manner, that it divided them into the first centuries and those coming afterward? Does the fifth, the tenth, etc. century likewise count among the first? one would ask; and in the same way I ask: Does the concept of the extended fall under metaphysics? You reply: Yes! Ah, but that of body as well? Yes! And that of the fluid body? You falter, for if things run on in this way, then everything will fall under metaphysics. From this it is plain that the bare degree of subordination (the particular set beneath the general) cannot mark out the boundaries of a science, but rather, in our case, the utter dissimilarity and diversity of origin. What further clouded the root idea of metaphysics on yet another side was that, being cognition a priori, it displays a certain kinship with mathematics — a kinship that, so far as the a priori origin goes, does make the two akin; but so far as concerns the manner of cognizing from concepts in the one, set against the manner of judging simply through the construction of concepts a priori in the other, and thus the difference between a philosophical cognition and a mathematical one, there stands revealed a heterogeneity so pronounced that, though one always somehow sensed it, one could never reduce it to distinct criteria. It has thereby come to pass that, philosophers having themselves gone astray in unfolding the idea of their science, the working of it could possess no fixed aim and no reliable measuring-line, and that, saddled with so arbitrary a draft, in the dark as to the road they should take, and forever quarreling among themselves over the discoveries each insisted he had made along his own, they dragged their science first into others' contempt and in the end even into their own.

All pure cognition a priori thereby forms, in virtue of the particular cognitive faculty within which alone it can be lodged, a unity of its own, and metaphysics is that philosophy whose task is to set forth this cognition in such systematic unity. Its speculative part, which has claimed this title for itself above all — the part we call the metaphysics of nature, which weighs everything, insofar as it is (not what ought to be), out of concepts a priori — is now partitioned as follows.

Metaphysics in the narrower sense, so named, is made up of two parts: the transcendental philosophy and the physiology of pure reason. The first of these attends solely to the understanding and to reason as such within a system comprising all those concepts and principles that bear upon objects as such, positing no objects that would be given (Ontologia); the second attends to nature, that is, to the totality of given objects (be they given to the senses or, should one wish, to some other manner of intuition), and it is accordingly physiology (albeit only rationalis). Now within this rational contemplation of nature reason may be put to use in a manner either physical or hyperphysical — or, to phrase it better, either immanent or transcendent. The first bears upon nature to the extent that cognition of it admits of application within experience (in concreto); the second bears upon that linkage among the objects of experience which oversteps experience altogether. This transcendent physiology thus takes for its object either an inner linkage or an outer one, both of which, though, run past possible experience; the first is the physiology of the whole of nature, that is, transcendental cognition of the world, the second that of the whole of nature's tie with a being above nature, that is, transcendental cognition of God.

Immanent physiology, on the other hand, views nature as the totality of all objects of the senses, and hence as it is given to us, though solely under those conditions a priori on which it can be given to us at all. Its objects, however, are of just two sorts: 1. Those belonging to the outer senses, and so the totality of them, corporeal nature. 2. The object of the inner sense, the soul, and, by its basic concepts generally, thinking nature. The metaphysics of corporeal nature is termed physics — but, since it is meant to hold only the a priori principles of its cognition, rational physics. The metaphysics of thinking nature is termed psychology, and for the cause just adduced only its rational cognition is here to be understood.

The full system of metaphysics accordingly rests on four principal parts: 1. The ontology. 2. The rational physiology. 3. The rational cosmology. 4. The rational theology. The second part — namely the doctrine of nature belonging to pure reason — embraces two subdivisions, the physica rationalis⁷⁵ and the psychologia rationalis.

The primordial idea of a philosophy of pure reason itself dictates this partition; the partition is therefore architectonic, answering to its essential ends, and not merely technical, arranged by kinships noticed at random and, so to say, on a gamble — and just for that reason it is also unalterable and legislative. Yet several points crop up here that stir misgiving and might sap one's conviction of its lawfulness.

In the first place, how am I to look for a cognition a priori, and so a metaphysics, of objects insofar as they are handed to our senses and thus a posteriori? and how can it be done, to cognize the nature of things by principles a priori and to reach a rational physiology ? The reply runs thus: from experience we borrow nothing beyond what is needed in order to give ourselves an object, partly of the outer, partly of the inner sense. The one comes about by the bare concept of matter (impenetrable, lifeless extension), the other by the concept of a thinking being (within the empirical inner representation: I think). For the rest, throughout the entire metaphysics of these objects we should have to hold ourselves back wholly from any empirical principle that might tack some further experience onto the concept so as to draw from it a judgment about these objects.

In the second place: what then becomes of empirical psychology, which from of old has held its ground within metaphysics, and from which, in our times, so much has been anticipated toward illuminating it, once the hope of accomplishing anything usable a priori was abandoned? My reply: it must be assigned there where the proper (empirical) doctrine of nature has its place — that is, on the flank of applied philosophy, to which pure philosophy contributes the principles a priori, so that the former must be bound up with it, yet not commingled. Empirical psychology must therefore be banished outright from metaphysics, and by the very idea of metaphysics it already stands wholly shut out. All the same, in keeping with scholastic practice one will yet still have to concede it a small corner there (albeit only by way of episode), and that on grounds of economy, since it is not yet rich enough to constitute a study on its own, and yet too weighty to be thrown out altogether or fastened somewhere else, where it would find even less affinity than in metaphysics. It is thus no more than a stranger lodged for the time being, granted a stay for a while, until in a full-scale anthropology (the counterpart to the empirical doctrine of nature) he can take up quarters of his own.

Such, then, is the general idea of metaphysics, which — because more was at first expected of it than can in fairness be demanded, and because for a while people indulged themselves with pleasant expectations — sank in the end into general disdain, once they found their hope betrayed. From the whole run of our critique one will by now be amply persuaded of this: that, granted metaphysics cannot serve as the bedrock of religion, it must nevertheless remain at all times as its rampart , and that human reason — dialectical already through the bent of its own nature — can never dispense with a science of this kind, one that curbs it and, by means of a scientific and perfectly luminous self-knowledge, holds off the ravages that an unbridled speculative reason would otherwise, quite without fail, work upon morals as well as religion. One may thus be assured — however aloof or dismissive those carry on who know how to appraise a science not by its nature but purely by its incidental effects — that we shall time and again come back to it as to a beloved from whom we have been estranged, for reason, where essential ends are here in question, is bound to labor without rest either toward searching insight or toward the wrecking of sound insights already possessed.

Metaphysics, then — of nature as much as of morals — and above all the critique of a reason that dares to fly on its own wings, which runs ahead by way of preliminary exercise (propaedeutically), is really the one thing that alone constitutes what we can, in the true sense, call philosophy. Philosophy so understood refers everything to wisdom, but by the road of science — the only road which, once it has been opened, never grows over again and suffers no wanderings astray. Mathematics, natural science, and even the empirical acquaintance with the human being carry a high worth as means — for the most part toward contingent, but in the last resort toward necessary and essential ends of mankind — yet only then through the mediation of a cognition of reason out of bare concepts, which, call it what you will, is at bottom nothing but metaphysics.

For precisely this reason metaphysics is likewise the crowning of every cultivation of human reason, indispensable even should one leave out of account its bearing as a science upon certain determinate ends. For it examines reason in respect of its elements and supreme maxims, which must themselves underlie the possibility of certain sciences and the use of them all. That, as mere speculation, it does more to fend off errors than to widen cognition detracts nothing from its worth; on the contrary, it lends it dignity and standing through the censorial office, which safeguards the general order and harmony — indeed the prosperity — of the scientific commonwealth and keeps its daring and fertile labors from drifting away from the chief end, the happiness of all.

Chapter 4. The History of Pure Reason

This title stands here merely to designate a place that is left vacant in the system and will have to be supplied at some future point. I content myself with casting, from a purely transcendental vantage point—namely the nature of pure reason—a fleeting glance over the whole of the treatments it has so far received, which to my eye admittedly presents edifices, yet only ones lying in ruins.

It is remarkable enough—though in the nature of things it could not have been otherwise—that human beings, in the childhood of philosophy, set out from precisely where we would now rather come to rest, namely by first taking up the cognition of God, together with the hope—or even the makeup—of a world beyond. Whatever crude religious concepts the ancient usages, surviving from a time even prior to the peoples' rude condition, may have brought in, this did not keep the more enlightened part from dedicating themselves to free inquiry into this object, and it was easy to see that no more solid and trustworthy way of pleasing the invisible power that rules the world—so as to be happy at least in another world—could be found than a good conduct of life. Theology and morals were on that account the two mainsprings—or better, the two points of reference—for all those abstracted inquiries of reason to which people have ever since given themselves. The former, meanwhile, was really what drew merely speculative reason, little by little, into that business which subsequently grew so famous under the title of metaphysics.

I will not now separate out the periods on which this or that transformation of metaphysics happened to fall, but only present, in a rapid outline, the difference of idea that prompted its principal revolutions. And there I find a threefold aim under which the most significant transformations were founded upon this stage of controversy.

1. As regards the object to which all our cognitions of reason refer, some were merely sensual-, others merely intellectual philosophers. Epicurus can be called the foremost philosopher of sensibility, Plato that of the intellectual realm. This distinction between the schools, however subtle it may be, dates back to the very earliest times and long persisted without a break. The adherents of the former maintained that actuality resides solely in the objects of the senses and that all the rest is fancy; the adherents of the second held, on the contrary: within the senses nothing is found but semblance, and the understanding alone cognizes what is true. On that account the former did not, for all that, deny reality to the concepts of the understanding, yet in their hands this reality was only logical, while in the hands of the others it was mystical. The former, while granting intellectual concepts, took only sensible objects to be given. The latter, by contrast, held the true objects to be merely intelligible and posited an intuition carried out through the pure understanding—one attended by no senses and, on their view, only thrown into confusion by them.

2. As concerns the origin of pure cognitions of reason—as to whether they are drawn from experience or, independently of it, find their source in reason. Aristotle can be taken as the leader of the empiricists, and Plato as that of the noologists. Locke, who in more recent days took the side of the former, and Leibniz, who took that of the latter (albeit at a sufficient distance from the latter's mystical system), have all the same proved unable to bring this quarrel to any decision. At least Epicurus, for his part, went about his sensual system far more consistently (for in his inferences he never once passed beyond the frontier of experience) than did Aristotle and Locke (but above all the latter), who, having drawn every concept and principle from experience, presses their use so far as to hold that God's existence and the immortality of the soul (although both objects lie wholly beyond the limits of possible experience) can be demonstrated every bit as evidently as some theorem of mathematics.

3. As to method. If anything at all is to bear the name of method, it must be a procedure conducted according to principles. Now the method presently dominant in this branch of investigation admits of a division into the naturalistic and the scientific. The naturalist where pure reason is concerned adopts as his principle: that on the loftiest questions making up the task of metaphysics more is to be achieved by ordinary reason without science (which he styles sound reason) than by way of speculation. He thus asserts that the size and remoteness of the moon can be settled with more assurance by the estimate of the eye than through mathematical detours. It is sheer misology raised to principles and—what is more preposterous than anything—the disregard of all artful means, trumpeted as a distinctive method for broadening one's cognition. For as far as those naturalists are concerned who act from a want of fuller insight, nothing can with good ground be charged against them. They keep to ordinary reason without parading their ignorance as a method that is supposed to hold the secret of drawing truth up from Democritus's deep well. Quod sapio, satis est mihi, non ego curo esse quod Arcesilas aerumnosique Solones (Pers.) is their watchword, under which they may, content and worthy of approval, pass their days without troubling over science or throwing its business into disarray.

As for those who observe a scientific method, they are here free to proceed either dogmatically or skeptically, though under every circumstance bound to proceed systematically. If for the first of these I here name the celebrated Wolff, and for the second David Hume, I may, consistent with my present aim, leave the others unnamed. The critical path alone still lies open. If the reader has shown the good will and patience to walk through it in my company, he may now judge whether—should he care to add his own contribution toward turning this footpath into a highroad—what many centuries were unable to accomplish might not be reached before the present one has run its course: that is, to grant human reason full contentment in the very matter that has forever engaged its craving to know, though thus far to no avail.