Immanuel Kant

Critique of Pure Reason

II. Transcendental Doctrine of Method

Chapter III. The Architectonic of Pure Reason.

By the term architectonic I mean the art of constructing a system. Without systematic unity, our knowledge cannot become science; it will be an aggregate, and not a system. Thus architectonic is the doctrine of the scientific in cognition, and therefore necessarily forms part of our methodology.

Reason cannot permit our knowledge to remain in an unconnected and rhapsodistic state, but requires that the sum of our cognitions should constitute a system. It is thus alone that they can advance the ends of reason. By a system I mean the unity of various cognitions under one idea. This idea is the conception - given by reason - of the form of a whole, in so far as the conception determines a priori not only the limits of its content, but the place which each of its parts is to occupy. The scientific idea contains, therefore, the end and the form of the whole which is in accordance with that end. The unity of the end, to which all the parts of the system relate, and through which all have a relation to each other, communicates unity to the whole system, so that the absence of any part can be immediately detected from our knowledge of the rest; and it determines a priori the limits of the system, thus excluding all contingent or arbitrary additions. The whole is thus an organism (articulatio), and not an aggregate (coacervatio); it may grow from within (per intussusceptionem), but it cannot increase by external additions (per appositionem). It is, thus, like an animal body, the growth of which does not add any limb, but, without changing their proportions, makes each in its sphere stronger and more active.

We require, for the execution of the idea of a system, a schema, that is, a content and an arrangement of parts determined a priori by the principle which the aim of the system prescribes. A schema which is not projected in accordance with an idea, that is, from the standpoint of the highest aim of reason, but merely empirically, in accordance with accidental aims and purposes (the number of which cannot be predetermined), can give us nothing more than technical unity. But the schema which is originated from an idea (in which case reason presents us with aims a priori, and does not look for them to experience), forms the basis of architectonical unity. A science, in the proper acceptation of that term. cannot be formed technically, that is, from observation of the similarity existing between different objects, and the purely contingent use we make of our knowledge in concreto with reference to all kinds of arbitrary external aims; its constitution must be framed on architectonical principles, that is, its parts must be shown to possess an essential affinity, and be capable of being deduced from one supreme and internal aim or end, which forms the condition of the possibility of the scientific whole. The schema of a science must give a priori the plan of it (monogramma), and the division of the whole into parts, in conformity with the idea of the science; and it must also distinguish this whole from all others, according to certain understood principles.

No one will attempt to construct a science, unless he have some idea to rest on as a proper basis. But, in the elaboration of the science, he finds that the schema, nay, even the definition which he at first gave of the science, rarely corresponds with his idea; for this idea lies, like a germ, in our reason, its parts undeveloped and hid even from microscopical observation. For this reason, we ought to explain and define sciences, not according to the description which the originator gives of them, but according to the idea which we find based in reason itself, and which is suggested by the natural unity of the parts of the science already accumulated. For it will of ten be found that the originator of a science and even his latest successors remain attached to an erroneous idea, which they cannot render clear to themselves, and that they thus fail in determining the true content, the articulation or systematic unity, and the limits of their science.

It is unfortunate that, only after having occupied ourselves for a long time in the collection of materials, under the guidance of an idea which lies undeveloped in the mind, but not according to any definite plan of arrangement - nay, only after we have spent much time and labour in the technical disposition of our materials, does it become possible to view the idea of a science in a clear light, and to project, according to architectonical principles, a plan of the whole, in accordance with the aims of reason. Systems seem, like certain worms, to be formed by a kind of generatio aequivoca - by the mere confluence of conceptions, and to gain completeness only with the progress of time. But the schema or germ of all lies in reason; and thus is not only every system organized according to its own idea, but all are united into one grand system of human knowledge, of which they form members. For this reason, it is possible to frame an architectonic of all human cognition, the formation of which, at the present time, considering the immense materials collected or to be found in the ruins of old systems, would not indeed be very difficult. Our purpose at present is merely to sketch the plan of the architectonic of all cognition given by pure reason; and we begin from the point where the main root of human knowledge divides into two, one of which is reason. By reason I understand here the whole higher faculty of cognition, the rational being placed in contradistinction to the empirical.

If I make complete abstraction of the content of cognition, objectively considered, all cognition is, from a subjective point of view, either historical or rational. Historical cognition is cognitio ex datis, rational, cognitio ex principiis. Whatever may be the original source of a cognition, it is, in relation to the person who possesses it, merely historical, if he knows only what has been given him from another quarter, whether that knowledge was communicated by direct experience or by instruction. Thus the Person who has learned a system of philosophy - say the Wolfian - although he has a perfect knowledge of all the principles, definitions, and arguments in that philosophy, as well as of the divisions that have been made of the system, possesses really no more than an historical knowledge of the Wolfian system; he knows only what has been told him, his judgements are only those which he has received from his teachers. Dispute the validity of a definition, and he is completely at a loss to find another. He has formed his mind on another's; but the imitative faculty is not the productive. His knowledge has not been drawn from reason; and although, objectively considered, it is rational knowledge, subjectively, it is merely historical. He has learned this or that philosophy and is merely a plaster cast of a living man. Rational cognitions which are objective, that is, which have their source in reason, can be so termed from a subjective point of view, only when they have been drawn by the individual himself from the sources of reason, that is, from principles; and it is in this way alone that criticism, or even the rejection of what has been already learned, can spring up in the mind.

All rational cognition is, again, based either on conceptions, or on the construction of conceptions. The former is termed philosophical, the latter mathematical. I have already shown the essential difference of these two methods of cognition in the first chapter. A cognition may be objectively philosophical and subjectively historical - as is the case with the majority of scholars and those who cannot look beyond the limits of their system, and who remain in a state of pupilage all their lives. But it is remarkable that mathematical knowledge, when committed to memory, is valid, from the subjective point of view, as rational knowledge also, and that the same distinction cannot be drawn here as in the case of philosophical cognition. The reason is that the only way of arriving at this knowledge is through the essential principles of reason, and thus it is always certain and indisputable; because reason is employed in concreto - but at the same time a priori - that is, in pure and, therefore, infallible intuition; and thus all causes of illusion and error are excluded. Of all the a priori sciences of reason, therefore, mathematics alone can be learned. Philosophy - unless it be in an historical manner - cannot be learned; we can at most learn to philosophize.

Philosophy is the system of all philosophical cognition. We must use this term in an objective sense, if we understand by it the archetype of all attempts at philosophizing, and the standard by which all subjective philosophies are to be judged. In this sense, philosophy is merely the idea of a possible science, which does not exist in concreto, but to which we endeavour in various ways to approximate, until we have discovered the right path to pursue - a path overgrown by the errors and illusions of sense - and the image we have hitherto tried in vain to shape has become a perfect copy of the great prototype. Until that time, we cannot learn philosophy - it does not exist; if it does, where is it, who possesses it, and how shall we know it? We can only learn to philosophize; in other words, we can only exercise our powers of reasoning in accordance with general principles, retaining at the same time, the right of investigating the sources of these principles, of testing, and even of rejecting them.

Until then, our conception of philosophy is only a scholastic conception - a conception, that is, of a system of cognition which we are trying to elaborate into a science; all that we at present know being the systematic unity of this cognition, and consequently the logical completeness of the cognition for the desired end. But there is also a cosmical conception (conceptus cosmicus) of philosophy, which has always formed the true basis of this term, especially when philosophy was personified and presented to us in the ideal of a philosopher. In this view philosophy is the science of the relation of all cognition to the ultimate and essential aims of human reason (teleologia rationis humanae), and the philosopher is not merely an artist - who occupies himself with conceptions - but a lawgiver, legislating for human reason. In this sense of the word, it would be in the highest degree arrogant to assume the title of philosopher, and to pretend that we had reached the perfection of the prototype which lies in the idea alone.

The mathematician, the natural philosopher, and the logician - how far soever the first may have advanced in rational, and the two latter in philosophical knowledge - are merely artists, engaged in the arrangement and formation of conceptions; they cannot be termed philosophers. Above them all, there is the ideal teacher, who employs them as instruments for the advancement of the essential aims of human reason. Him alone can we call philosopher; but he nowhere exists. But the idea of his legislative power resides in the mind of every man, and it alone teaches us what kind of systematic unity philosophy demands in view of the ultimate aims of reason. This idea is, therefore, a cosmical conception.*

[*Footnote: By a cosmical conception, I mean one in which all men necessarily take an interest; the aim of a science must accordingly be determined according to scholastic conceptions, if it is regarded merely as a means to certain arbitrarily proposed ends.]

In view of the complete systematic unity of reason, there can only be one ultimate end of all the operations of the mind. To this all other aims are subordinate, and nothing more than means for its attainment. This ultimate end is the destination of man, and the philosophy which relates to it is termed moral philosophy. The superior position occupied by moral philosophy, above all other spheres for the operations of reason, sufficiently indicates the reason why the ancients always included the idea - and in an especial manner - of moralist in that of philosopher. Even at the present day, we call a man who appears to have the power of self-government, even although his knowledge may be very limited, by the name of philosopher.

The legislation of human reason, or philosophy, has two objects- nature and freedom - and thus contains not only the laws of nature, but also those of ethics, at first in two separate systems, which, finally, merge into one grand philosophical system of cognition. The philosophy of nature relates to that which is, that of ethics to that which ought to be.

But all philosophy is either cognition on the basis of pure reason, or the cognition of reason on the basis of empirical principles. The former is termed pure, the latter empirical philosophy.

The philosophy of pure reason is either propaedeutic, that is, an inquiry into the powers of reason in regard to pure a priori cognition, and is termed critical philosophy; or it is, secondly, the system of pure reason - a science containing the systematic presentation of the whole body of philosophical knowledge, true as well as illusory, given by pure reason - and is called metaphysic. This name may, however, be also given to the whole system of pure philosophy, critical philosophy included, and may designate the investigation into the sources or possibility of a priori cognition, as well as the presentation of the a priori cognitions which form a system of pure philosophy - excluding, at the same time, all empirical and mathematical elements.

Metaphysic is divided into that of the speculative and that of the practical use of pure reason, and is, accordingly, either the metaphysic of nature, or the metaphysic of ethics. The former contains all the pure rational principles - based upon conceptions alone (and thus excluding mathematics) - of all theoretical cognition; the latter, the principles which determine and necessitate a priori all action. Now moral philosophy alone contains a code of laws - for the regulation of our actions - which are deduced from principles entirely a priori. Hence the metaphysic of ethics is the only pure moral philosophy, as it is not based upon anthropological or other empirical considerations. The metaphysic of speculative reason is what is commonly called metaphysic in the more limited sense. But as pure moral philosophy properly forms a part of this system of cognition, we must allow it to retain the name of metaphysic, although it is not requisite that we should insist on so terming it in our present discussion.

It is of the highest importance to separate those cognitions which differ from others both in kind and in origin, and to take great care that they are not confounded with those with which they are generally found connected. What the chemist does in the analysis of substances, what the mathematician in pure mathematics, is, in a still higher degree, the duty of the philosopher, that the value of each different kind of cognition, and the part it takes in the operations of the mind, may be clearly defined. Human reason has never wanted a metaphysic of some kind, since it attained the power of thought, or rather of reflection; but it has never been able to keep this sphere of thought and cognition pure from all admixture of foreign elements. The idea of a science of this kind is as old as speculation itself; and what mind does not speculate - either in the scholastic or in the popular fashion? At the same time, it must be admitted that even thinkers by profession have been unable clearly to explain the distinction between the two elements of our cognition - the one completely a priori, the other a posteriori; and hence the proper definition of a peculiar kind of cognition, and with it the just idea of a science which has so long and so deeply engaged the attention of the human mind, has never been established. When it was said: "Metaphysic is the science of the first principles of human cognition," this definition did not signalize a peculiarity in kind, but only a difference in degree; these first principles were thus declared to be more general than others, but no criterion of distinction from empirical principles was given. Of these some are more general, and therefore higher, than others; and - as we cannot distinguish what is completely a priori from that which is known to be a posteriori - where shall we draw the line which is to separate the higher and so-called first principles, from the lower and subordinate principles of cognition? What would be said if we were asked to be satisfied with a division of the epochs of the world into the earlier centuries and those following them? "Does the fifth, or the tenth century belong to the earlier centuries?" it would be asked. In the same way I ask: Does the conception of extension belong to metaphysics? You answer, "Yes." Well, that of body too? "Yes." And that of a fluid body? You stop, you are unprepared to admit this; for if you do, everything will belong to metaphysics. From this it is evident that the mere degree of subordination - of the particular to the general - cannot determine the limits of a science; and that, in the present case, we must expect to find a difference in the conceptions of metaphysics both in kind and in origin. The fundamental idea of metaphysics was obscured on another side by the fact that this kind of a priori cognition showed a certain similarity in character with the science of mathematics. Both have the property in common of possessing an a priori origin; but, in the one, our knowledge is based upon conceptions, in the other, on the construction of conceptions. Thus a decided dissimilarity between philosophical and mathematical cognition comes out - a dissimilarity which was always felt, but which could not be made distinct for want of an insight into the criteria of the difference. And thus it happened that, as philosophers themselves failed in the proper development of the idea of their science, the elaboration of the science could not proceed with a definite aim, or under trustworthy guidance. Thus, too, philosophers, ignorant of the path they ought to pursue and always disputing with each other regarding the discoveries which each asserted he had made, brought their science into disrepute with the rest of the world, and finally, even among themselves.

All pure a priori cognition forms, therefore, in view of the peculiar faculty which originates it, a peculiar and distinct unity; and metaphysic is the term applied to the philosophy which attempts to represent that cognition in this systematic unity. The speculative part of metaphysic, which has especially appropriated this appellation - that which we have called the metaphysic of nature - and which considers everything, as it is (not as it ought to be), by means of a priori conceptions, is divided in the following manner.

Metaphysic, in the more limited acceptation of the term, consists of two parts - transcendental philosophy and the physiology of pure reason. The former presents the system of all the conceptions and principles belonging to the understanding and the reason, and which relate to objects in general, but not to any particular given objects (Ontologia); the latter has nature for its subject-matter, that is, the sum of given objects - whether given to the senses, or, if we will, to some other kind of intuition - and is accordingly physiology, although only rationalis. But the use of the faculty of reason in this rational mode of regarding nature is either physical or hyperphysical, or, more properly speaking, immanent or transcendent. The former relates to nature, in so far as our knowledge regarding it may be applied in experience (in concreto); the latter to that connection of the objects of experience, which transcends all experience. Transcendent physiology has, again, an internal and an external connection with its object, both, however, transcending possible experience; the former is the physiology of nature as a whole, or transcendental cognition of the world, the latter of the connection of the whole of nature with a being above nature, or transcendental cognition of God.

Immanent physiology, on the contrary, considers nature as the sum of all sensuous objects, consequently, as it is presented to us - but still according to a priori conditions, for it is under these alone that nature can be presented to our minds at all. The objects of immanent physiology are of two kinds: 1. Those of the external senses, or corporeal nature; 2. The object of the internal sense, the soul, or, in accordance with our fundamental conceptions of it, thinking nature. The metaphysics of corporeal nature is called physics; but, as it must contain only the principles of an a priori cognition of nature, we must term it rational physics. The metaphysics of thinking nature is called psychology, and for the same reason is to be regarded as merely the rational cognition of the soul.

Thus the whole system of metaphysics consists of four principal parts: 1. Ontology; 2. Rational Physiology; 3. Rational cosmology; and 4. Rational theology. The second part - that of the rational doctrine of nature - may be subdivided into two, physica rationalis* and psychologia rationalis.

[*Footnote: It must not be supposed that I mean by this appellation what is generally called physica general is, and which is rather mathematics than a philosophy of nature. For the metaphysic of nature is completely different from mathematics, nor is it so rich in results, although it is of great importance as a critical test of the application of pure understanding-cognition to nature. For want of its guidance, even mathematicians, adopting certain common notions- which are, in fact, metaphysical - have unconsciously crowded their theories of nature with hypotheses, the fallacy of which becomes evident upon the application of the principles of this metaphysic, without detriment, however, to the employment of mathematics in this sphere of cognition.]

The fundamental idea of a philosophy of pure reason of necessity dictates this division; it is, therefore, architectonical - in accordance with the highest aims of reason, and not merely technical, or according to certain accidentally-observed similarities existing between the different parts of the whole science. For this reason, also, is the division immutable and of legislative authority. But the reader may observe in it a few points to which he ought to demur, and which may weaken his conviction of its truth and legitimacy.

In the first place, how can I desire an a priori cognition or metaphysic of objects, in so far as they are given a posteriori? and how is it possible to cognize the nature of things according to a priori principles, and to attain to a rational physiology? The answer is this. We take from experience nothing more than is requisite to present us with an object (in general) of the external or of the internal sense; in the former case, by the mere conception of matter (impenetrable and inanimate extension), in the latter, by the conception of a thinking being - given in the internal empirical representation, I think. As to the rest, we must not employ in our metaphysic of these objects any empirical principles (which add to the content of our conceptions by means of experience), for the purpose of forming by their help any judgements respecting these objects.

Secondly, what place shall we assign to empirical psychology, which has always been considered a part of metaphysics, and from which in our time such important philosophical results have been expected, after the hope of constructing an a priori system of knowledge had been abandoned? I answer: It must be placed by the side of empirical physics or physics proper; that is, must be regarded as forming a part of applied philosophy, the a priori principles of which are contained in pure philosophy, which is therefore connected, although it must not be confounded, with psychology. Empirical psychology must therefore be banished from the sphere of metaphysics, and is indeed excluded by the very idea of that science. In conformity, however, with scholastic usage, we must permit it to occupy a place in metaphysics - but only as an appendix to it. We adopt this course from motives of economy; as psychology is not as yet full enough to occupy our attention as an independent study, while it is, at the same time, of too great importance to be entirely excluded or placed where it has still less affinity than it has with the subject of metaphysics. It is a stranger who has been long a guest; and we make it welcome to stay, until it can take up a more suitable abode in a complete system of anthropology - the pendant to empirical physics.

The above is the general idea of metaphysics, which, as more was expected from it than could be looked for with justice, and as these pleasant expectations were unfortunately never realized, fell into general disrepute. Our Critique must have fully convinced the reader that, although metaphysics cannot form the foundation of religion, it must always be one of its most important bulwarks, and that human reason, which naturally pursues a dialectical course, cannot do without this science, which checks its tendencies towards dialectic and, by elevating reason to a scientific and clear self-knowledge, prevents the ravages which a lawless speculative reason would infallibly commit in the sphere of morals as well as in that of religion. We may be sure, therefore, whatever contempt may be thrown upon metaphysics by those who judge a science not by its own nature, but according to the accidental effects it may have produced, that it can never be completely abandoned, that we must always return to it as to a beloved one who has been for a time estranged, because the questions with which it is engaged relate to the highest aims of humanity, and reason must always labour either to attain to settled views in regard to these, or to destroy those which others have already established.

Metaphysic, therefore - that of nature, as well as that of ethics, but in an especial manner the criticism which forms the propaedeutic to all the operations of reason - forms properly that department of knowledge which may be termed, in the truest sense of the word, philosophy. The path which it pursues is that of science, which, when it has once been discovered, is never lost, and never misleads. Mathematics, natural science, the common experience of men, have a high value as means, for the most part, to accidental ends - but at last also, to those which are necessary and essential to the existence of humanity. But to guide them to this high goal, they require the aid of rational cognition on the basis of pure conceptions, which, be it termed as it may, is properly nothing but metaphysics.

For the same reason, metaphysics forms likewise the completion of the culture of human reason. In this respect, it is indispensable, setting aside altogether the influence which it exerts as a science. For its subject-matter is the elements and highest maxims of reason, which form the basis of the possibility of some sciences and of the use of all. That, as a purely speculative science, it is more useful in preventing error than in the extension of knowledge, does not detract from its value; on the contrary, the supreme office of censor which it occupies assures to it the highest authority and importance. This office it administers for the purpose of securing order, harmony, and well-being to science, and of directing its noble and fruitful labours to the highest possible aim - the happiness of all mankind.

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Critique of Pure Reason by Immanuel Kant