indeed, the common fate of human reason in speculation, to finish the imposing edifice of thought as rapidly as possible, and then for the first time to begin to examine whether the
foundation
solid one or no.
Kant - Critique of Pure Reason
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will render an important service to reason, by substituting the certainty of scientific method for that random groping after results without the guidance of principles, which has hit her U characterised the pursuit of metaphysical studies. It will render an important service to the inquiring mind of youth, by leading the student to apply his powers to the cultivation of genuine science, instead of wasting them, as at present, on speculations which can never lead to any result, or on the idle attempt to invent new ideas and opinions. But, above all, it will confer an inestimable benefit on morality and religion, by showing that all the objections urged against them may be silenced for ever by the Socratic method, that is to say, by proving the ignorance of the objector. For, as the world has never been, and, no doubt, never will be, without a system of metaphysics of one kind or another, it is the highest and weightiest concern of philosophy to render it powerless for harm, by closing up the sources of error.
This important change in the field of the sciences, this loss of its fancied possessions, to which speculative reason must submit, does not prove in any way detrimental to the general interests of humanity. The advantages which the world has derived from the teachings of pure reason, are not at all im paired. The loss falls, in its whole extent, on the monopoly of the schools, but does not in the slightest degree touch the ? '<<- teresls of mankind. I appeal to the most obstinate dogmatist, whether the proof of the continued existence of the soul after death, derived from the simplicity of its substance ; of the freedom of the will in opposition to the general mechanism of nature, drawn from the subtle but impotent distinction of sub jective and objective practical necessity ; or of the existence of God, deduced from the conception of an ens realissimum, --the contingency of the changeable, and the necessity of a prime mover, has ever been able to pass beyond the limits of the schools, to penetrate the public mind, or to exercise the slightest influence on its convictions. It must be admitted
that this has not been the case, and that, owing to the unfitness of the common understanding for such subtle speculations, it can never be expected to take place. On the contrary, it it plain that the hope of a future life arises from the feeling, which exists in the breast of every man, that the temporal it inadenuate to meet and satisfy the dcmnpda of his rnturfl.
? ? ? ? PREFACE TO THE SECOND EDITION. xxxvii
In like manner, it cannot be doubted that the clear exhibition of duties in opposition to all the claims of inclination, gives rise to the consciousness of freedom, and that the glorious order, beauty, and providential care, everywhere displayed in nature, give rise to the belief in a wise and great Author of the Universe. Such is the genesis of these general convictions of mankind, so far as they depend on rational grounds ; and this public property not only remains undisturbed, but is even raised to greater importance, by the doctrine that the schools have no right to arrogate to themselves a more profound insight into a matter of general human concernment, than that to which the great mass of men, ever held by us in the highest estimation, can without difficulty attain, and that the schools should therefore confine themselves to the elaboration of these universally comprehensible, and, from a moral point of view, amply satisfactory proofs. The change, therefore, affects only the arrogant pretensions of the schools, which would gladly retain, in their own exclusive possession, the key to the truths which they impart to the public.
Quod mecum nescit, solus vult scire videri.
At the same time it does not deprive the speculative philoso pher of his just title to be the sole depos. tor of a science which benefit* the public without its knowledge -- I meau, the Critique of Pure Reason. This can never berime popular, and, indeed, has no occasion to be so; for fne-spun argu ments in favour of useful truths, make just as little impression on the public mind as the equally subtle objections brought against these truths. On the other hand, since both inevitably force themselves on every man who rises to the height of speculation, it becomes the manifest duty of the schools to enter upon a thorough investigation of the rights of specula tive reason, and thus to prevent the scandal which metaphysical controversies are sure, sooner or later, to cause even to the masses. It is only by criticism that metaphysicians (and, as snch, theologians too) can be saved from these controversies and from the consequent perversion of their doctrines. Criti cism alone can strike a blow at the root of Materialism, Fatal
ism, Atheism, Free-thinking, Fanaticism, and Superstition, which are universally injurious -- as well as of Idealism and Scepticism, which are dangerous to the schools, but can scorcelj
? ? ? ? ixxviii PREFACE TO THE 8F. COKD EDITION.
pass over to the public. If governments think proper to in terfere with the affairs of the learned, it would be more con sistent with a wise regard for the interests of science, as well as for those of society, to favour a criticism of this kind, by which alone the labours of reason can be established on a firm basis, than to support the ridiculous despotism of the schools, which raise a loud cry of danger to the public over the de struction of cobwebs, of which the public lias never taken any notice, and the loss of which, therefore, it can never feel.
This critical science is not opposed to the dogmatic proce dure of reason iu pure cognition ; for pure cognition must n I ways be dogmatic, that is, must rest on strict demonstration from sure principles a priori -- but to dogmatism, that to (he presumption that possible to make any progress with
pure cognition, derived from (philosophical) conceptions, according to the principles which reason has long been in the habit of employing-- without first inquiring in what way and
what right reason has come into the possession of these principles. Dogmatism thus the dogmatic procedure of pure reason without previous criticism of its own powers, and in opposing this procedure, we must not be supposed to lend any countenance to that loquacious shallowness which arro gates to itself the name of popularity, nor yet to scepticism, which makes short work with the whole science of metaphy sics. On the contrary, our criticism the necessary pre paration for thoroughly scientific system of metaphysics, which must perform its task entirely a priori, to the com plete satisfaction of speculative reason, and must, therefore, lie treated, not popularly, but scholastic-ally. In carrying out the plan which the Critique prescribes, that is, in the future sys tem of metaphysics, we must have recourse to the strict method of the celebrated Wolf, the greatest of all dogmatic philoso phers. He was the first to point out the necessity of establishing fixed principles, of clearly defining our conceptions, and
our demonstrations to the most severe scrutiny, instead of rashly jumping at conclusions. The example which he set, served to awaken that spirit of profound and thorough investigation which not yet extinct in Germany. He would have been peculiarly well fitted to give truly scientific cha racter to metaphysical studies, had occurred to him to pre pare the field bv criticism of the organum, that of pure
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reason itself. That he failed to perceive the necessity of such a procedure, must be ascribed to the dogmatic mode of thought which characterized his age, and on this point the philosophers of his time, as well as of all previous times, have nothing to reproach each other with. Those who reject at once the method of Wolf, and of the Critique of Pure Reason, can haze no. other aim but to shake off the fetters of science, to change labour into sport, certainty into opinion, and philosophy into philodoxy.
sible, to remove the difficulties and obscurity, which, without
fault of mine perhaps, have given rise to many misconceptions even among acute thinkers. In the propositions themselves, and in the demonstrations by which they are supported, a? well as in the form and the entire plan of the work, I have found nothing to alter ; which must be attributed partly to the long examination to which I had subjected the whole before offering it to the public, and partly to the nature of the case. For pure speculative reason is an organic structure in which there is nothing isolated or independent, but every single part is essential to all the rest ; and hence, the slightest imperfection, whether defect or positive error, could not fail to betray itself in use. I venture, further to hope, that this system will maintain the same unalterable character for the future. I am led to entertain this confidence, not by vanity, but by the evidence which the equality of the result affords, when we proceed, first, from the simplest elements up to the complete whole of pure reason, and then, backwards from the whole to each individual part. We find that the attempt to make the
slightest alteration, in any part, leads inevitably to contradic tions, not merely in this system, but in human reason itself. At the same time, there is still much room for improvement in the exposition of the doctrines contained in this work. In the present edition, I have endeavoured to remove misappre hensions of the esthetical part, especially with regard to the conception of Time ; to clear away the obscurity which has been found in the deduction of the conceptions of the under standing ; to supply the supposed want oT sufficient evidence in the demonstration of the principles of lie pure understand, ing ; and, lastly, to obviate the misunderstanding of the paralo gisms which immediately precede the Rational Psychology.
In this second edition, I have endeavoured, as far as pos
? ? ? ? XI fin: face ro toe second editi i*.
Beyond this poiut--the end of the second Maitt Division of the Transcendental Dialectic -- I hnve not extended my altera tions,* partly from want of tice, and partly because I am
* The only addition, properly so called --and that only in the method of proof--which I have made in the present edition, consists of a new refutation of psychological Idealism, and a strict demonstration -- the only one possible, as I believe-- of the objective reality of external intuition However harmless Idealism may be considered-- although in reality it is not so--in regard to the essential ends of metaphysics, it must still remain a scandal to philosophy and to the general human reason to be obliged to assume, as an article of mere belief, the existence of things external to ourselves (from which, yet, we derive the whole material of cognition even for the internal sense), and not to lie able to oppose a satisfactory proof to any one who may call it in question. As there is some obscurity of ex pression in the demonstration as it stands in the text, I propose to alter the passage in question as follows : " But this permanent cannot be an in tuition in me. For all the determining grounds of my existence which can be found in me, are representations, and, as such, do themselves re quire a permanent, distinct from them, which may determine my existence in relation to their changes, that my existence in time, wherein they change. " may, probably, be urged in opposition to this proof, that, after all, am only conscious immediately of that which in me, that
of my representation of external things, and that, consequently, must always remain uncertain whether anything corresponding to this repre sentation, does or does not exist externally to me. But am conscious, through internal experience, of my existence hi time, (consequently, also, ol the determinability of the former in the latter), and that more than the simple consciousness of my representation. in fact, the same as the
empirical consciousness of my existence, which can oidy be determined relation to something, which, while connected with my existence, ex ternal to me. This consciousness of my existence in time is, therefore, identical with the consciousness of relation to something external to me, and is, therefore, experience, not fiction, sense, not imagination, which inseparably connects the external with my intemal sense. For the ex ternal sense is, in itself, the relation of intuition to something real, ex ternal to me and the reality of this something, as opposed to the mere imagination of it, rests solely on its inseparable connection with internal experience as the condition of its possibility. with the intellectual consciousness of my existence, in the representation am, which accom panies all my judgments, and all the operations of my understanding, could, at the same time, connect determination of my existence in- tellectual intuition, then the consciousness of relation to something ex ternal to me would not be necessary. But the internal intuition in which alone my existence can he determined, though preceded by that purely intellectual consciousne itself sensible and attached to the condition of time. Hence this ermination of my existence, and consequently my internal experience itself, must depend on something permanent which is not in me, which can be. therefore, only in something external to me, to which must look upon myself as k'i laljd. Thus the eality
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not aware that any portion of the remainder bas given rise tc misconceptions among intelligent and impartial critics, whom I do not here mention with that praise which is their due, hut who will find that their suggestions have been attended to in the work itself.
In attempting to render the exposition of my views as intel
ligible as possible, I have been compelled to leave out 01 abridge various passages which were not essential to the com pleteness of the work, but which many readers might consider useful in other respects, and might be unwilling to miss. This trifling loss, which could not be avoided without swelling the book beyond due limits, may be supplied, at the pleasure of the reader, by a comparison with the first edition, and will, I hope, be more than compensated for by the greater clearness of the exposition as it now stands.
I have observed, with pleasure and thankfulness, in the pages of various reviews and treatises, that the spirit of pro found and thorough investigation is not extinct in Germany, though it may have been overborne and silenced for a time by the fashionable tone of a licence in thinking, which gives itself the airs of genius --and that the difficulties which beset the paths of Criticism have not prevented energetic and acute thinkers from making themselves masters of the science of pure reason to which these paths conduct--a science which
? the external sense is necessarily connected with that of the internal, in order to the possibility of experience in general ; that am just as certainly conscious that there are things external to me related to my sense, as am that myself exist, as determined in time. But in order to ascertain to what given intuitions objects, external to me, really correspond, in other words, what intuitions belong to the external sense and not to imagination, must have recourse, in every particular case, to those rules according to which experience in general (even internal experience) distinguished from imagination, and which are always based on the pro position that there really an external experience. --We may add the reirarlc, that the representation of something permanent in existence, not the same thing as the permanent representation for representation may be very variable and changing -- as all our representations, even
that of matter, are -- and yet refer to something permanent, which must, therefore, be distinct from all my representations and external to me, the existence of which necessarily included in thf termination of my owa
existence, and with constitutes one experien t--an experience which would not even be possible internally, were not also at the same time, in part, external. To the question How we are no more able to reply, than we are, in general, to think the stationary in time, the co -existence which with the variable, produces the conception of change.
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u not popular, but scholastic in its charac'cr, and which alone can hope for a lasting existence or possess au abiding value. To these deserving men, who so happily combine profundity of view with a talent for lucid exposition -- a talent which I myself am not conscious of possessing --I leave the task of removing any obscurity which may still adhere to the statement of my doctrines. For, in this case, the danger is not that of being refuted, but of being misunderstood. For my own part, I must henceforward abstain from controversy, although I shall carefully attend to all suggestions, whether from friends or adversaries, which may be of use in the future elaboration of the system of this Propedeutic. As, during these labours, I have advanced pretty far in years -- this month
I reach my sixty-fourth year -- it will be necessary for me to economize time, if I am to carry out my plan of elaborating the Metaphysics of Nature as well as of Morals, in confirmation
)f the correctness of the principles established in this Critique af Pure Reason, both Speculative and Practical ; and I must, therefore, leave the task of clearing up the obscurities of the present work -- inevitable, perhaps, at the outset -- as well as the defence of the whole, to those deserving men who have made my system their own. A philosophical system cannot come forward armed at all points like a mathematical treatise, and hence it may be quite possible to take objection to parti cular passages, while the organic structure of the system, con sidered as a unity, has no danger to apprehend. But few possess the ability, and still fewer the inclination, to take a comprehensive view of a new system. By confining the view to particular passages, taking these out of their connection and comparing them with one another, it is easy to pick out apparent contradictions, especially in a work written with any freedom of style. These contradictions place the work in an unfavourable light in the eyes of those who rely on the judg ment of others, but are easily reconciled by those who have mastered the idea of the whole. If a theory possesses stabi lity in itself, the action and reaction which seemed at first to threaten its existence, serve only, in the course of time, to smooth down any s\ erficial roughness or inequality, and -- if men of insight, im irtiality, and truly popular gifts, turn their attention to it -- to secure to short time, the requj-
<<ite elegance also.
Iv nig9bf. ro, April 1787.
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I. Or TEE DIFFERENCE BETWEEN PURE AND SMITHICI L KNOWLEDGE.
That all our knowledge begins with experience there can be no doubt. For how is it possible that the faculty of cog nition should be awakened into exercise otherwise than by means of objects which affect our senses, and partly of them<< selves produce representations, partly rouse our powers ol understanding into activity, to compare, to connect, or to se parate these, and so to convert the raw material of our sensuous impressions into a knowledge of objects, which is called ex perience? In respect of time, therefore, no knowledge cf ours is antecedent to experience, but begins with it.
But, though nll our knowledge begins with experience, it by no means follows, that all arises out of experience. For,
on the contrary, it is quite possible that our empirical know ledge is a compound of that which we receive through im pressions, and that which the faculty of cognition supplies from itself (sensuous impressions giving merely the occasion), an addition which we cannot distinguish from the original element given by sense, till long practice has made us at tentive to, and skilful in separating it. It is, therefore, a question which requires close investigation, and is not to be answered at first sight, -- whether there exists a knowledge altogether independent of experience, and even of all sensuous impressions ? Knowledge of this kind is called a priori, in contradistinction to empirical knowledge, which has its sources a posteriori, that in experience.
? But the expression, " priori," not as yet definite
enough, adequately to indicate the whole meaning of. tht question above started. For, in speaking cf knowledge wukh
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has its sources In experience, we are wont to say, that this or
that may be known ii priori, because we do not derive thia
knowledge immediately from experience, but from a general rule, which, however, we have itself borrowed from experi ence. Thus, if a man undermined his house, we say, " he might know h priori that it would have fallen ;" that he needed not to have waited for the experience that did actu ally fall. But still, priori, he could not know even this much. For, that bodies are heavy, and, consequently, that they fall when their supports are taken away, must have been known to him previously, by means of experience.
? By the term " knowledge priori," therefore, we stall in the sequel understand, not such as independent of this or that kind of experience, but such as absolutely so of all ex perience. Opposed to this empirical knowledge, or that which possible only a posteriori, that is, through experi ence. Knowledge priori either pure or impure. Pure knowledge priori that with which no empirical element mixed up. For example, the proposition, " Every change has cause," proposition priori, but impure, because change conception which can only he derived from expe rience.
II. The nuMAX intellect, even in an unfhilosofhical STATE, IS IN POSSESSION OF CERTAIN COGNITIONS PRIORI.
The question now as to criterion, by which we may
securely distinguish pure from an empirical cognition. Ex perience no doubt teaches us that this or that object con stituted in such and such manner, but not that could not possibly exist otherwise. Now, in the first place, we have
proposition which contains the idea of necessity in its very conception, judgment priori moreover, not derived from any other proposition, unless from one equally involving the idea of necessity, absolutely priori. Se condly, an empirical judgment never exhibits strict and abso lute, but only assumed and comparative universality (by in duction) therefore, the most we can say --so far as we have hitherto observed, there
rule. If, on the other hand, and absolute universality, that
no exception to this or that judgment carries with strict
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tion, it is not derived from experience, but is valid absolutely a priori.
Empirical universality is, therefore, only an arbitrary ex tension of validity, from that which may be predicated of a proposition valid in most cases, to that which is asserted of a proposition which holds good in all ; as, for example, in the affirmation, " all bodies are heavy. '
strict universality characterizes a judgment, it necessarily indicates another peculiar source of knowledge, namely, a faculty of cognition <i priori. Necessity and strict univer sality, therefore, are infallible tests for distinguishing pure from empirical knowledge, and are inseparably connected with each other. But as in the use of these criteria the empirical limitation is sometimes more easily detected than the contingency of the judgment, or the unlimited universality which we attach to a judgment is often a more convincing proof than its necessity, it may be advisable to use the criteria separately, each being by itself infallible.
? Now, that in the sphere of human cognition, we have judgments which are necessary, and in the strictest sense universal, consequently pure ii priori, it will be an easy matter to shew. If we desire an example from the sciences,
we need only take any proposition in mathematics. If
we cast our eyes upon the commonest operations of the un
derstanding, the proposition, " every change must have a cause," will amply serve our purpose. In the latter case, indeed, the conception of a cause so plainly involves the con ception of a necessity of connexion with an effect, and of a strict universality of the law, that the very notion of a cause would entirely disappear, were we to derive like Hume, from frequent association of what happens with that which precedes, and the habit thence originating of connecting re presentations --the necessity inherent in the judgment being therefore merely subjective. Besides, without seeking for such examples of principles existing priori in cognition, we might easily shew that such principles are the indispen sable basis of the possibility of experience itself, and con sequently prove their existence priori. For whence could our experience itself acquire certainty, all the rules on which
depends were themselves empirical, and consequently for tuitous No one, therefore, can admit the validity of the use
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of sucb rules as first principles. But, for the present, we may content ourselves with having established the fact, that we do possess and exercise a faculty of pure a priori cog nition ; and, secondly, with having pointed out the proper teats of such cognition, namely, universality and necessity.
Not only in judgments, however, hut even in conceptions, is an A priori origin manifest. For example, if we take away by degrees from our conceptions of a body all that can be referred to mere sensuous experience--colour, hardness or eoftness, weight, even impenetrability -- the body will then vanish ; but the space which it occupied still remains, and this it is utterly impossible to annihilate in thought. Again, if we take away, in like manner, from our empirical conception
of any object, corporeal or incorporeal, all properties which mere experience has taught us to connect with still we cannot think away those through which we cogitate as substance, or adhering to substance, although our conception of substance more determined than that of an object. Compelled, therefore, by that necessity with which the con ception of substance forces itself upon us, we must confess that has its seat in our faculty of cognition priori.
III. PniLOSOPHY STANDS IN NEED OF A SCIENCE WHICH SHALL DETERMINE THE POSSIBILITY, PRINCIPLES, AND EXTENT OF HUMAN KNOWLEDGE PRIORI.
Of far more importance than all that has been above said, the consideration that certain of our cognitions rise com
pletely above the sphere of all possible experience, and by means of conceptions, to which there exists in the whole ex tent of experience no corresponding object, seem to extend the range of our jndgments beyond its bounds. And just in this transcendental or supersensible sphere, where experience affords us neither instruction nor guidance, lie die investi gations of Reason, which, on account of their importance, we consider far preferable to, and as having far more elevated aim than, all that the understanding can achieve within the sphere of sensuous phenomena. So high value do we set upon these investigations, that even at the risk of error, we persist in following them out, and permit neither doubt nor disregard nor indifference to restrain us from the pur suit. These unavoidable problems of mere pure reason are
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God, Freedom (of will) and Immortality. The science which, with all its preliminaries, has for its especial object the solution of these problems is named metaphysics, --a science which is at the very outset dogmatical, that con fidently takes upon itself the execution of this task without
any previous investigation of the ability or inability of reason for such an undertaking.
Now the safe ground of experience being thus abandoned, seems nevertheless natural thst we should hesitate to erect building with the cognitions we possess, without knowing whence they come, and on the strength of principles, the origin of whirh undiscovered. Instead of thus trying to build without foundation, rather to be expected that
we should long ago have put the question, how the under
can arrive at these priori cognitions, and what the extent, validity, and worth which they may possess We say, this natural enough, meaning by the word natural, that which consistent with just and reasonable way of think ing but we understand by the term, that which usually happens, nothing indeed could be mere natural and more
some evident contradiction, we hurry on undoubtingly in our course. This, however, may be avoided, we are suffi ciently cautious in the construction of our fictions, which are not the less fictions on that account.
Mathematical science affords us brilliant example, how far, independently of all experience, we may carry our priori knowledge. true that the mathematician occupies himself with objects and cognitions only in so far as they can be represented by means of intuition. But this circumstance
easily overlooked, because the said intuition can itself be given priori, and therefore hardly to be distinguished from mere pure conception. Deceived such proof of
? standing
than that this investigation should be left
comprehensible
long unattempted. For one part of our pure knowledge, the science of mathematics, has been long firmly estab lished, and thus leads us to form flattering expectations with regard to others, though these may be of quite different nature. Besides, when we get beyond the bounds of ex perience, we are of course safe from opposition in that quarter and the charm of widening the range of our know ledge so great, that unless we are brought to stand-still
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IKTBODUCTIOIT.
the power of reason, we can perceive no limits to the ex tension of our knowledge. The light dove cleaving in free flight the thin air, whose resistance it feels, might imagine that her movements would he far more free and rapid in air less space. Just in the same way did Plato, abandoning the world of sense because of the narrow limits it sets to the understanding, venture upon the wings of ideas beyond into the void space of pure intellect. He did not reflect that he made no real progress by all his efforts for he met with no resistance which might serve him for support, as were, whereon to rest, and on which he might apply his powers, in order to let the intellect acquire momentum for its progress.
indeed, the common fate of human reason in speculation, to finish the imposing edifice of thought as rapidly as possible, and then for the first time to begin to examine whether the foundation solid one or no. Arrived at this point, all sorts of excuses are sought after, in order to console us for its want of stability, or rather indeed, to enable us to dispense
altogether with so late and dangerous an investigation. But what frees us during the process of building from all appre hension or suspicion, and flatters us into the belief of its solidity, this. great part, perhaps the greatest part, of the business of our reason consists in the analyxation of the
which we already possess of objects. By this means we gain multitude of cognitions, which although really nothing more than elucidations or explanations of that which (though in confused manner) was already thought in our conceptions, are, at least in respect of their form, prized as new introspections whilst, so far as regards their matter or content, we have really made no addition to our con ceptions, but only disinvolved them. But as this process does furnish r? al priori knowledge,* which has sure progress and useful results, reason, deceived this, slips in, without being itself aware of assertions of quite different kind; in which, to given conceptions adds others, priori in deed, but entirely foreign to them, without our knowing how
arrives at these, and, indeed, without such question ever suggesting itself. shall therefore at once proceed to examine the difference between these two modes of knowledge.
Not ivnthetical. -- Tr.
? conceptions
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IV. Or TnE DTFFEHENCE BETWEEN ANALYTICAL AND 6TNTUETICAL JUDGMENTS.
In all judgments wherein the relation of a subject to the pre
dicate is cogitated, (I mention affirmative judgments only
here ; the application to negative will be very easy,) this rela
tion is possible in two different ways. Either the predicate
B belongs to the subject A, as somewhat which is contained
(though covertly) in the conception A ; or the predicate B
lies completely out of the conception A, although it stands in connexion with it. In the first instance, I term the judgment
analytical, in the second, synthetical. Analytical judgments
are therefore those in which the connection of the predicate with the subject is cogitated through identity ; those in which this connexion is cogitated without identity, are called synthetical judgments. The former may be called explicative, the latter augmentative* judgments ; because the former add in the predicate nothing to the conception of the subject, but only analyse it into its constituent conceptions, which were thought already in the subject, although in a con fused manner ; the latter add to our conceptions of the subject a predicate which was not contained in and which no analysis could ever have discovered therein. For example, when say, "all bodies are extended," this an analytical judgment. For need not go beyond the conception of body
order to find extension connected with but merely analyse the conception, that is, become conscious of the manifold properties which think in that conception, in order to discover this predicate in therefore an ana lytical judgment. On the other hand, when say, " all bodies are heavy," the predicate something totally different from that which think in the mere conception of
By the addition of such predicate therefore, becomes synthetical judgment.
Judgments of experience, as such, are always synthetical. For would be absurd to think of grounding an analytical
judgment on experience, because in forming such judg ment, need not go out of the sphere of my conceptions,
That is, judgments which reahy add to, and do not merely analy
or explain the conceptions which make up the torn of our knowledge. 7V.
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and therefore recourse"to the testimony of experience is quite unnecessary. That bodies are extended" is not an em pirical judgment, but a proposition which stands firm ft priori. For before addressing myself to experience, I already have in my conception all the requisite conditions for the judg ment, and I have only to extract the predicate from the concep tion, according to the principle of contradiction, and thereby at the same time become conscious of the necessity of the judgment, a necessity which I could never learn from ex
On the other hand, though at first I do not at all
perience.
include the predicate of weight in my conception of body in general, that, conception still indicates an object of ex
? perience, a part of the totality of experience, to which I can still add other parts ; and this I do when I recognize by ob servation that bodies are heavy. I can cognize beforehand by analysis the conception of body through the character istics of extension, impenetrability, shape, &c, all which are cogitated in this conception. But now I extend my know ledge, and looking back on experience from which I had derived this conception of body, I find weight at all times connected with the above chsracteristics, and therefore I synthetically add to my conceptions this as a predicate, and say, " all bodies are heavy. " Thus it is experience upon which rests the possibility of the synthesis of the predicate of weight with the conception of body, because both con ceptions, although the one is not contained in the other, still belong to one another (only contingently, however), as parts of a whole, namely, of experience, which is itself a synthesis of intuitions.
But to synthetical judgments a priori, such aid is entirely wanting. If I go out of and beyond the conception A, in order to recognize another B as connected with what foundation have to rest on, whereby to render the synthesis possible have here no longer the advantage of looking out in the sphere of experience for what want. Let us
take, for example, the proposition, "everything that happens has cause. " In the conception of something that happens, indeed think an existence which certnin time antecedes,
and from this can derive analytical judgments. But the conception of cause lies quite out of the above " conception, tad indicates something entirely different from that which
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? SYNTHETICAL JUDGMENTS A PRIOBI.
9
happens," and is consequently not contained in that con ception. How then am I able to assert concerning the general conception -- "that which happens " -- something entirely dif ferent from that conception, and to recognize the conception of cause although not contained in yet as belonging to and even necessarily? what here the unknown = upon which the understanding rests when believes has found, out of the conception foreign predicate which nevertheless considers to be connected with cannot be experience, because the principle adduced annexes the two represent ations, cause and effect, to the representation existence, not only with universality, which experience cannot give, but also with the expression of necessity, therefore completely prion and from pure conceptions. Upon such synthetical, that augmentative propositions, depends the whole aim of our specu lative knowledge priori for although analytical
? judgments are indeed highly important and necessary, they are so, only
to arrive at that clearness of conceptions which requisite for sure and extended synthesis, and this alone real acquisition.
V. In all theobetical sciences of season, synthetical JUDGMENTS PRIORI ABB CONTAINED AS PBISCIPLES.
Matiiematicax judgments are always synthetical. Hitherto this fact, though incontestibly true and very important in its consequences, seems to have escaped the analysts of the human mind, nay, to be in complete opposition to all their conj'c tures. For as was found that mathematical conclusions all
proceed according to the principle of contradiction (whi<. h the nature of every apodeictic certainty requires), people became persuaded that the fundamental principles of the science also were recognised and admitted in the same way. But the notion fallacious for although synthetical pro position can certainly be discerned by means of the principle of contradiction, this possible only when another syntheti cal proposition precedes, from which the latter deduced, but never of itself.
Before all, be observed, that proper mathematical propo
sitions are always judgments priori, and not empirical, be cause they carry nlong with them the conception of necessity,
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which cannot be given by experience. If this be demurred to, it matters not ; I will then limit my assertion to pure ma thematics, the very conception of which implies, that it con sists of knowledge altogether non-empirical and a priori.
We might, indeed, at first suppose that the proposition 7 + 5=12, is a merely analytical proposition, following (ac cording to the principle of contradiction), from the concep tion of a sum of seven and five. But if we regard it more narrowly, we find that our conception of the sum of seven and five contains nothing more than the uniting of both sums into one, whereby it cannot at all be cogitated what this single number is which embraces both. The conception of twelve is by no means obtained by merely cogitating the union of seven and five ; and we may analyze our conception of such a possible sum as long as we will, still we shall never dis cover in it the notion of twelve. We must go beyond these conceptions, and have recourse to an intuition which corresponds to one of the two,--our five fingers, for ex ample, or like Segner in his "Arithmetic," five points, and so by degrees, add the units contained in the five given in the intuition, to the conception of seven. For I first take the number 7, and, for the conception of 5 calling in the aid of the fingers of my hand as objects of intuition, I add the units, which I before took together to make up the number
5, gradually now by means of the material image my hand, to the number 7, and by this process, I at length see the number 12 arise. That 7 should be added to 5, I have ceriainly cogitated in my conception of a sum=7-r5, but not that this sum was equal to 12. Arithmetical propositions are therefore always synthetical, of which we may become more clearly convinced by trying large numbers. For it wih thus become quite evident, that turn and twist our conceptions as we may, it is impossible, without having recourse to intui tion, to arrive at the sum total or product by means of the mere analysis of our conceptions. Just as little is any princi ple of pure geometry analytical. " A straight line between
two points is the shortest," is a synthetical proposition. For my conception of straight, contains no notion of quantity, but is merely qualitative. The conception of the shortest is therefore wholly an addition, and by no analysis can it be ex tracted from our conception of a straight line. Intuition
? ? ? ? SYNTHETICAL JUDGMENTS A PRIORI.
11
mast therefore here lend its aid, by means of which and thai only, our synthesis is possible.
Some few principles preposited by geometricians are, in deed, really analytical, and depend on the principle of con tradiction. They serve, however, like identical propositions, as links in the chain of method, not as principles, -- for ex ample, a=a, the whole is equal to itself, or (a+6) 7 a, the whole is greater than its part. And yet even these principles themselves, though they derive their validity from pure conceptions, are only admitted in mathematics because they can be presented in intuition. What causes us here
to believe that the predicate of such apodeictic judgments is already contained in our conception, and that
the judgment is therefore analytical, is merely the equivocal nature of the expression. We must join in thought a certain predicate to a given conception, and this necessity cleaves already to the conception. But the question not what we must join in thought to the given conception, but what we really think therein, though only obscurely, and then becomes manifest, that the predicate pertains to these conceptions, ne cessarily indeed, yet not as thought in the conception itself, out by virtue of an intuition, which must be added to the con ception.
2. The science of Natural Philosophy (Physics) contains in itself synthetical judgments priori, as principles. shall adduce two propositions. For instance, the proposition, " in all changes of the material world, the quantity of matter remains unchanged or, that, " in all communication of motion, action and re-action must always be equal. " In both of these, not only the necessity, and therefore their origin priori clear, but also that they are synthetical propo sitions. For in the conception of matter, do not cogitate
its permanency, but merely its presence in space, which fills. therefore really go out of and beyond the conception of matter, in order to think on to something priori, which did not think in it. The proposition therefore not analyti cal, but synthetical, and nevertheless conceived priori and so with regard to th<< other propositions of the pure part of natural philosophy.
3. As to Metaphysics, even we look upon merely as an attempted science, yet, from the nature of human reason, an
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indispensable one, we find that it must contain synthetical propositions & priori. It is not merely the duty of meta physics to dissect, and thereby analytically to illustrate the conceptions which we form a priori of things ; but we seek tc widen the range of our & priori knowledge. For this purpose, we must avail ourselves of such principles as add something tc the original conception --something not identical with, nor contained in and by means of synthetical judgments
priori, leave far behind us the limits of experience for example, in the proposition, " the world must have begin ning," and such like. Thus metaphysics, according to the proper aim of the science, consists merely of synthetical pro positions priori.
VI. The umrEB8AL problem of puee reasox.
? It extremely advantageous to be able to bring number of investigations under the formula of single problem. For in this manner, we not only facilitate our own labour, inas much as we define clearly to ourselves, but also render more easy for others to decide whether we have done justice to our undertaking. The proper problem of pure reason, then,
contained in the question, " How are synthetical judgments priori possible ? "
That metaphysical science has hitherto remained so va cillating state of uncertainty and contradiction, only to be attributed to the fact, that this great problem, and perhaps even the difference between analytical and synthetical judg ments, did not sooner suggest itself to philosophers. Upon the solution of this problem, or upon sufficient proof of the im possibility of synthetical knowledge priori, depends the existence or downfall of the science of metaphysics. Among
David Hume came the nearest of all to this problem yet never acquired in his mind sufficient preci sion, nor did he regard the question in its universality. On the contrary, he stopped short at the synthetical proposition ol the connection of an effect with its cause. , (principium causal- itatis), insisting that such proposition priori was impos sible. According to his conclusions, then, all that we term
philosophers,
science fancied insight of reason
metaphysical
from experience, and to
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of necessity. Against this assertion, destructive to all pure philosophy, he would have been guarded, had he had our problem before his eyes in its universality. For he would then have perceived that, according to his own argument, there likewise could not be any pure mathematical science, which assuredly cannot exist without synthetical propositions d priori, -- an absurdity from which his good understanding must have saved him.
In the solution of the above problem is at the same time comprehended the possibility of the use of pure reason in the foundation and construction of all sciences which contain theoretical knowledge & priori of objects, that is to say, the answer to the following questions :
? How is pure mathematical science possible ?
How is pure natural science possible ?
Respecting these sciences, as they do certainly exist, it may
with propriety be asked, how they are possible ? --for that they must be possible, is shewn by the fact of their really existing. * But as to metaphysics, the miserable progress it has hitherto made, and the fact that of no one system yet brought forward, as far as regards its true aim, can it be said that this science really exists, leaves any one at liberty to doubt with reason the very possibility of its existence.
Yet, in a certain sense,' this kind of knowledge must un questionably be looked upon as given; in other words, meta physics must be considered as really existing, if not as a science, nevertheless as a natural disposition of the human mind (metaphyska naturalis). For human reason, without any instigations imputable to the mere vanity of great know ledge, unceasingly progresses, urged on by its own feeling of need, towards such questions as cannot be answered by any em pirical application of reason, or principles derived therefrom ; and so there has ever really existed in every man some system
* As to the existence of pure natural science, or physics, perhaps many may still express doubts. But we have only to look at the different pro positions which are commonly treated of at the commencement of proper (empirical) physical science --those, for example, relating to the perma nence of the same quautity of matter, the vit inertia, the equality of action and reaction. &c. --to be soou convinced that ttiey form e science of pure physics {phyrica pur a, or rationalis), which well deserves to ha separately exposed as a special science, in its whole extent, whether thai be (rr<<n' or confined.
? ? ? u INTBODtJCTIOlT.
of metaphysics. It will always exist, so soon as reason awake* to the exercise of its power of speculation. And now the question arises -- How is metaphysics, as a natural disposition, possible ? In other words, how, from the nature of universal human reason, do those questions arise which pure reason proposes to itself, and which it is impelled by its own feeling
af need to answer as well as it can ?
But as in all the attempts hitherto made to answer the ques
tions which reason is prompted by its very nature to propose to itself, for example, whether the world had a beginning, or has existed from eternity, it has always met with unavoidable contradictions, we must not rest satisfied with the mere natu ral disposition of the mind to metaphysics, that with the existence of the faculty of pure reason, whence, indeed, some sort of metaphysical system always arises; but must be possible to arrive at certainty in regard to the question whether we know or do not know the things of which metaphysics treats. We must be able to arrive at decision on the subjects of its questions, or on the ability or inability of reason to form'
any judgment respecting them and therefore either to extend with confidence the bounds of our pure reason, or to set strictly defined and safe limits to its action. This last ques tion, which arises out of the above universal problem, would properly run thus How metaphysics possible as science
Thus, the critique of reason leads at last, naturally and necessarily, to science and, on the other hand, the dogma tical use of reason without criticism leads to groundless asser tions, against which others equally specious can always be set, thus ending unavoidably in scepticism.
Besides, this science cannot be of great and formidable prolixity, because has not to do with objects of reason, the variety of which inexhaustible, but merely with reason her self and her problems problems whieh arise out of her own bosom, and are not proposed to her the nature of outward 'things, but her own nature. And when once reason has previously become able completely to understand her own
power in regard to objects which she meets with in experience, will be easy to determine securely the extent and limits of
her attempted application to objects beyond the confines
? experience. mini, therefore, We may anJ
regard
the hitherto attempts
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made; to establish metaphysical science dogmatically as non existent. For what of analysis, that mere dissection of
contained in one or other, not the aim of, but only preparation for metaphysics proper, which has for its object the extension, by means of synthesis, of our a priori knowledge. And for this purpose, mere analysis of course useless, because only shews what contained in these conceptions, but not how we arrive, a priori, at them; and this her duty to shew, in order to be able afterwards to determine their valid use in regard to all objects of expe rience, to all knowledge general. But little self-denial, indeed, needed to give up these pretensions, seeing the undeniable, and in the dogmatic mode of procedure, in evitable contradictions of Reason with herself, have long since ruined the reputation of every system of metaphysics that has appeared up to this time. will require more firmness to remain undeterred by difficulty from within, and opposition from without, from endeavouring, method quite opposed to all those hitherto followed, to further the growth and fruitfulness of science indispensable to human reason -- science from which every branch has borne may be cut away, but whose roots remain indestructible.
VII. Idea and division of a pabticitlab science, ttnden THE NAME OF A CRITIQUE OF PuBE REASON.
From all that has been said, there results the idea of par ticular science, which may be called the Critique of Pvre Reason. For reason the faculty which furnishes us with the principles of knowledge priori. Hence, pure reason
the faculty which contains the principles of cognizing any thing absolutely priori. An Organon of pure reason would be a compendium of those principles according to which alone all pure cognitions priori can be obtained. The completely extended application of such an organon would afford us system of pure reason. As this, however, de manding great deal, and yet doubtful whether any extension of our knowledge be here possible, or so, in what cases we can regard science of the mere criticism of pure reason, its sources and limits, as the propcedeutie to ? yBtem of pure reason. Such science must not be called Doctrine, but only Criticie of pure Reason and iu use,
conceptions,
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in regard to speculation, would be only negative, hot to en large the bounds of, but to purify our reason, and to shield it against error, --which alone is no little gain. I apply the term transcendental to all knowledge which is not so much occu pied with objects as with the mode of our cognition of these objects, so far as this mode of cognition is possible a priori. A system of such conceptions would be called Transcendental Philosophy. But this, again, is still beyond the bounds of our present essay. For as such a science must contain a complete exposition not only of our synthetical a priori, but of our analytical & priori knowledge, it is of too wide a range for our present purpose, because we do not require to carry our analysis any farther than is necessary to understand, in their full extent, the principles of synthesis a priori, with which alone we have to do. This investigation, which we cannot properly call a doctrine, but only a transcendental critique, because it aims not at the enlargement, but at the correction and guidance of our knowledge, and is to serve as a touchstone of the worth or worthlessness of all know ledge a priori, is the sole object of our present essay. Such a critique is consequently, as far as possible, a preparation for an organon ; and if this new organon should be found to fail, at least for a canon of pure reason, according to which the complete system of the philosophy of pure reason, whether it extend or limit the bounds of that reason, might one day be set forth both analytically and synthetically. For that this is possible, nay, that such a system is not of so great extent as to preclude the hope of its ever being com
is evident. For we have not here to do with the nature of outward objects, which is infinite, but solely with the mind, which judges of the nature of objects, and, again, with the mind only in respect of its cognition & priori. And the object of our investigations, as it is not to be sought without, but altogether within ourselves, cannot remain con cealed, and in all probability is limited enough to be com pletely surveyed and fairly estimated, according to its worth or worthlessness. Still less let the reader here expect a critique of books and systems of pure reason ; our present object is exclusively a critique of the faculty of pure reason itself. Only when we make this critique our foundation, do we possess a pure touchstone for estimating the philosophical
? pleted,
? ? ? IDEA OF A UKITMiDl
OF PUKE HEA. SOIT. 17
value of ancient and modern writings on this subject; and without this criterion, the incompetent historian or judge decides upon and corrects the groundless assertions of others with his own, which have themselves just as little foundation.
Transcendental philosophy is the idea of a science, for
which the Critique of Pure Reason must sketch the whole
plan architectonically, that from principles, with full
guarantee for the validity and stability of all the parts which
enter into the building. the system of all the principles
of pure reason. If this Critique itself does not assume the
title of transcendental philosophy, only because, to be
complete system, ought to contain full analysis of all
human knowledge a priori. Our critique must, indeed, lay
before us complete enumeration of all the radical concep
tions which constitute the said pure knowledge.
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? XXXVi PliEFACE TO THE SECOND ETOTIOK.
will render an important service to reason, by substituting the certainty of scientific method for that random groping after results without the guidance of principles, which has hit her U characterised the pursuit of metaphysical studies. It will render an important service to the inquiring mind of youth, by leading the student to apply his powers to the cultivation of genuine science, instead of wasting them, as at present, on speculations which can never lead to any result, or on the idle attempt to invent new ideas and opinions. But, above all, it will confer an inestimable benefit on morality and religion, by showing that all the objections urged against them may be silenced for ever by the Socratic method, that is to say, by proving the ignorance of the objector. For, as the world has never been, and, no doubt, never will be, without a system of metaphysics of one kind or another, it is the highest and weightiest concern of philosophy to render it powerless for harm, by closing up the sources of error.
This important change in the field of the sciences, this loss of its fancied possessions, to which speculative reason must submit, does not prove in any way detrimental to the general interests of humanity. The advantages which the world has derived from the teachings of pure reason, are not at all im paired. The loss falls, in its whole extent, on the monopoly of the schools, but does not in the slightest degree touch the ? '<<- teresls of mankind. I appeal to the most obstinate dogmatist, whether the proof of the continued existence of the soul after death, derived from the simplicity of its substance ; of the freedom of the will in opposition to the general mechanism of nature, drawn from the subtle but impotent distinction of sub jective and objective practical necessity ; or of the existence of God, deduced from the conception of an ens realissimum, --the contingency of the changeable, and the necessity of a prime mover, has ever been able to pass beyond the limits of the schools, to penetrate the public mind, or to exercise the slightest influence on its convictions. It must be admitted
that this has not been the case, and that, owing to the unfitness of the common understanding for such subtle speculations, it can never be expected to take place. On the contrary, it it plain that the hope of a future life arises from the feeling, which exists in the breast of every man, that the temporal it inadenuate to meet and satisfy the dcmnpda of his rnturfl.
? ? ? ? PREFACE TO THE SECOND EDITION. xxxvii
In like manner, it cannot be doubted that the clear exhibition of duties in opposition to all the claims of inclination, gives rise to the consciousness of freedom, and that the glorious order, beauty, and providential care, everywhere displayed in nature, give rise to the belief in a wise and great Author of the Universe. Such is the genesis of these general convictions of mankind, so far as they depend on rational grounds ; and this public property not only remains undisturbed, but is even raised to greater importance, by the doctrine that the schools have no right to arrogate to themselves a more profound insight into a matter of general human concernment, than that to which the great mass of men, ever held by us in the highest estimation, can without difficulty attain, and that the schools should therefore confine themselves to the elaboration of these universally comprehensible, and, from a moral point of view, amply satisfactory proofs. The change, therefore, affects only the arrogant pretensions of the schools, which would gladly retain, in their own exclusive possession, the key to the truths which they impart to the public.
Quod mecum nescit, solus vult scire videri.
At the same time it does not deprive the speculative philoso pher of his just title to be the sole depos. tor of a science which benefit* the public without its knowledge -- I meau, the Critique of Pure Reason. This can never berime popular, and, indeed, has no occasion to be so; for fne-spun argu ments in favour of useful truths, make just as little impression on the public mind as the equally subtle objections brought against these truths. On the other hand, since both inevitably force themselves on every man who rises to the height of speculation, it becomes the manifest duty of the schools to enter upon a thorough investigation of the rights of specula tive reason, and thus to prevent the scandal which metaphysical controversies are sure, sooner or later, to cause even to the masses. It is only by criticism that metaphysicians (and, as snch, theologians too) can be saved from these controversies and from the consequent perversion of their doctrines. Criti cism alone can strike a blow at the root of Materialism, Fatal
ism, Atheism, Free-thinking, Fanaticism, and Superstition, which are universally injurious -- as well as of Idealism and Scepticism, which are dangerous to the schools, but can scorcelj
? ? ? ? ixxviii PREFACE TO THE 8F. COKD EDITION.
pass over to the public. If governments think proper to in terfere with the affairs of the learned, it would be more con sistent with a wise regard for the interests of science, as well as for those of society, to favour a criticism of this kind, by which alone the labours of reason can be established on a firm basis, than to support the ridiculous despotism of the schools, which raise a loud cry of danger to the public over the de struction of cobwebs, of which the public lias never taken any notice, and the loss of which, therefore, it can never feel.
This critical science is not opposed to the dogmatic proce dure of reason iu pure cognition ; for pure cognition must n I ways be dogmatic, that is, must rest on strict demonstration from sure principles a priori -- but to dogmatism, that to (he presumption that possible to make any progress with
pure cognition, derived from (philosophical) conceptions, according to the principles which reason has long been in the habit of employing-- without first inquiring in what way and
what right reason has come into the possession of these principles. Dogmatism thus the dogmatic procedure of pure reason without previous criticism of its own powers, and in opposing this procedure, we must not be supposed to lend any countenance to that loquacious shallowness which arro gates to itself the name of popularity, nor yet to scepticism, which makes short work with the whole science of metaphy sics. On the contrary, our criticism the necessary pre paration for thoroughly scientific system of metaphysics, which must perform its task entirely a priori, to the com plete satisfaction of speculative reason, and must, therefore, lie treated, not popularly, but scholastic-ally. In carrying out the plan which the Critique prescribes, that is, in the future sys tem of metaphysics, we must have recourse to the strict method of the celebrated Wolf, the greatest of all dogmatic philoso phers. He was the first to point out the necessity of establishing fixed principles, of clearly defining our conceptions, and
our demonstrations to the most severe scrutiny, instead of rashly jumping at conclusions. The example which he set, served to awaken that spirit of profound and thorough investigation which not yet extinct in Germany. He would have been peculiarly well fitted to give truly scientific cha racter to metaphysical studies, had occurred to him to pre pare the field bv criticism of the organum, that of pure
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reason itself. That he failed to perceive the necessity of such a procedure, must be ascribed to the dogmatic mode of thought which characterized his age, and on this point the philosophers of his time, as well as of all previous times, have nothing to reproach each other with. Those who reject at once the method of Wolf, and of the Critique of Pure Reason, can haze no. other aim but to shake off the fetters of science, to change labour into sport, certainty into opinion, and philosophy into philodoxy.
sible, to remove the difficulties and obscurity, which, without
fault of mine perhaps, have given rise to many misconceptions even among acute thinkers. In the propositions themselves, and in the demonstrations by which they are supported, a? well as in the form and the entire plan of the work, I have found nothing to alter ; which must be attributed partly to the long examination to which I had subjected the whole before offering it to the public, and partly to the nature of the case. For pure speculative reason is an organic structure in which there is nothing isolated or independent, but every single part is essential to all the rest ; and hence, the slightest imperfection, whether defect or positive error, could not fail to betray itself in use. I venture, further to hope, that this system will maintain the same unalterable character for the future. I am led to entertain this confidence, not by vanity, but by the evidence which the equality of the result affords, when we proceed, first, from the simplest elements up to the complete whole of pure reason, and then, backwards from the whole to each individual part. We find that the attempt to make the
slightest alteration, in any part, leads inevitably to contradic tions, not merely in this system, but in human reason itself. At the same time, there is still much room for improvement in the exposition of the doctrines contained in this work. In the present edition, I have endeavoured to remove misappre hensions of the esthetical part, especially with regard to the conception of Time ; to clear away the obscurity which has been found in the deduction of the conceptions of the under standing ; to supply the supposed want oT sufficient evidence in the demonstration of the principles of lie pure understand, ing ; and, lastly, to obviate the misunderstanding of the paralo gisms which immediately precede the Rational Psychology.
In this second edition, I have endeavoured, as far as pos
? ? ? ? XI fin: face ro toe second editi i*.
Beyond this poiut--the end of the second Maitt Division of the Transcendental Dialectic -- I hnve not extended my altera tions,* partly from want of tice, and partly because I am
* The only addition, properly so called --and that only in the method of proof--which I have made in the present edition, consists of a new refutation of psychological Idealism, and a strict demonstration -- the only one possible, as I believe-- of the objective reality of external intuition However harmless Idealism may be considered-- although in reality it is not so--in regard to the essential ends of metaphysics, it must still remain a scandal to philosophy and to the general human reason to be obliged to assume, as an article of mere belief, the existence of things external to ourselves (from which, yet, we derive the whole material of cognition even for the internal sense), and not to lie able to oppose a satisfactory proof to any one who may call it in question. As there is some obscurity of ex pression in the demonstration as it stands in the text, I propose to alter the passage in question as follows : " But this permanent cannot be an in tuition in me. For all the determining grounds of my existence which can be found in me, are representations, and, as such, do themselves re quire a permanent, distinct from them, which may determine my existence in relation to their changes, that my existence in time, wherein they change. " may, probably, be urged in opposition to this proof, that, after all, am only conscious immediately of that which in me, that
of my representation of external things, and that, consequently, must always remain uncertain whether anything corresponding to this repre sentation, does or does not exist externally to me. But am conscious, through internal experience, of my existence hi time, (consequently, also, ol the determinability of the former in the latter), and that more than the simple consciousness of my representation. in fact, the same as the
empirical consciousness of my existence, which can oidy be determined relation to something, which, while connected with my existence, ex ternal to me. This consciousness of my existence in time is, therefore, identical with the consciousness of relation to something external to me, and is, therefore, experience, not fiction, sense, not imagination, which inseparably connects the external with my intemal sense. For the ex ternal sense is, in itself, the relation of intuition to something real, ex ternal to me and the reality of this something, as opposed to the mere imagination of it, rests solely on its inseparable connection with internal experience as the condition of its possibility. with the intellectual consciousness of my existence, in the representation am, which accom panies all my judgments, and all the operations of my understanding, could, at the same time, connect determination of my existence in- tellectual intuition, then the consciousness of relation to something ex ternal to me would not be necessary. But the internal intuition in which alone my existence can he determined, though preceded by that purely intellectual consciousne itself sensible and attached to the condition of time. Hence this ermination of my existence, and consequently my internal experience itself, must depend on something permanent which is not in me, which can be. therefore, only in something external to me, to which must look upon myself as k'i laljd. Thus the eality
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not aware that any portion of the remainder bas given rise tc misconceptions among intelligent and impartial critics, whom I do not here mention with that praise which is their due, hut who will find that their suggestions have been attended to in the work itself.
In attempting to render the exposition of my views as intel
ligible as possible, I have been compelled to leave out 01 abridge various passages which were not essential to the com pleteness of the work, but which many readers might consider useful in other respects, and might be unwilling to miss. This trifling loss, which could not be avoided without swelling the book beyond due limits, may be supplied, at the pleasure of the reader, by a comparison with the first edition, and will, I hope, be more than compensated for by the greater clearness of the exposition as it now stands.
I have observed, with pleasure and thankfulness, in the pages of various reviews and treatises, that the spirit of pro found and thorough investigation is not extinct in Germany, though it may have been overborne and silenced for a time by the fashionable tone of a licence in thinking, which gives itself the airs of genius --and that the difficulties which beset the paths of Criticism have not prevented energetic and acute thinkers from making themselves masters of the science of pure reason to which these paths conduct--a science which
? the external sense is necessarily connected with that of the internal, in order to the possibility of experience in general ; that am just as certainly conscious that there are things external to me related to my sense, as am that myself exist, as determined in time. But in order to ascertain to what given intuitions objects, external to me, really correspond, in other words, what intuitions belong to the external sense and not to imagination, must have recourse, in every particular case, to those rules according to which experience in general (even internal experience) distinguished from imagination, and which are always based on the pro position that there really an external experience. --We may add the reirarlc, that the representation of something permanent in existence, not the same thing as the permanent representation for representation may be very variable and changing -- as all our representations, even
that of matter, are -- and yet refer to something permanent, which must, therefore, be distinct from all my representations and external to me, the existence of which necessarily included in thf termination of my owa
existence, and with constitutes one experien t--an experience which would not even be possible internally, were not also at the same time, in part, external. To the question How we are no more able to reply, than we are, in general, to think the stationary in time, the co -existence which with the variable, produces the conception of change.
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u not popular, but scholastic in its charac'cr, and which alone can hope for a lasting existence or possess au abiding value. To these deserving men, who so happily combine profundity of view with a talent for lucid exposition -- a talent which I myself am not conscious of possessing --I leave the task of removing any obscurity which may still adhere to the statement of my doctrines. For, in this case, the danger is not that of being refuted, but of being misunderstood. For my own part, I must henceforward abstain from controversy, although I shall carefully attend to all suggestions, whether from friends or adversaries, which may be of use in the future elaboration of the system of this Propedeutic. As, during these labours, I have advanced pretty far in years -- this month
I reach my sixty-fourth year -- it will be necessary for me to economize time, if I am to carry out my plan of elaborating the Metaphysics of Nature as well as of Morals, in confirmation
)f the correctness of the principles established in this Critique af Pure Reason, both Speculative and Practical ; and I must, therefore, leave the task of clearing up the obscurities of the present work -- inevitable, perhaps, at the outset -- as well as the defence of the whole, to those deserving men who have made my system their own. A philosophical system cannot come forward armed at all points like a mathematical treatise, and hence it may be quite possible to take objection to parti cular passages, while the organic structure of the system, con sidered as a unity, has no danger to apprehend. But few possess the ability, and still fewer the inclination, to take a comprehensive view of a new system. By confining the view to particular passages, taking these out of their connection and comparing them with one another, it is easy to pick out apparent contradictions, especially in a work written with any freedom of style. These contradictions place the work in an unfavourable light in the eyes of those who rely on the judg ment of others, but are easily reconciled by those who have mastered the idea of the whole. If a theory possesses stabi lity in itself, the action and reaction which seemed at first to threaten its existence, serve only, in the course of time, to smooth down any s\ erficial roughness or inequality, and -- if men of insight, im irtiality, and truly popular gifts, turn their attention to it -- to secure to short time, the requj-
<<ite elegance also.
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I. Or TEE DIFFERENCE BETWEEN PURE AND SMITHICI L KNOWLEDGE.
That all our knowledge begins with experience there can be no doubt. For how is it possible that the faculty of cog nition should be awakened into exercise otherwise than by means of objects which affect our senses, and partly of them<< selves produce representations, partly rouse our powers ol understanding into activity, to compare, to connect, or to se parate these, and so to convert the raw material of our sensuous impressions into a knowledge of objects, which is called ex perience? In respect of time, therefore, no knowledge cf ours is antecedent to experience, but begins with it.
But, though nll our knowledge begins with experience, it by no means follows, that all arises out of experience. For,
on the contrary, it is quite possible that our empirical know ledge is a compound of that which we receive through im pressions, and that which the faculty of cognition supplies from itself (sensuous impressions giving merely the occasion), an addition which we cannot distinguish from the original element given by sense, till long practice has made us at tentive to, and skilful in separating it. It is, therefore, a question which requires close investigation, and is not to be answered at first sight, -- whether there exists a knowledge altogether independent of experience, and even of all sensuous impressions ? Knowledge of this kind is called a priori, in contradistinction to empirical knowledge, which has its sources a posteriori, that in experience.
? But the expression, " priori," not as yet definite
enough, adequately to indicate the whole meaning of. tht question above started. For, in speaking cf knowledge wukh
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has its sources In experience, we are wont to say, that this or
that may be known ii priori, because we do not derive thia
knowledge immediately from experience, but from a general rule, which, however, we have itself borrowed from experi ence. Thus, if a man undermined his house, we say, " he might know h priori that it would have fallen ;" that he needed not to have waited for the experience that did actu ally fall. But still, priori, he could not know even this much. For, that bodies are heavy, and, consequently, that they fall when their supports are taken away, must have been known to him previously, by means of experience.
? By the term " knowledge priori," therefore, we stall in the sequel understand, not such as independent of this or that kind of experience, but such as absolutely so of all ex perience. Opposed to this empirical knowledge, or that which possible only a posteriori, that is, through experi ence. Knowledge priori either pure or impure. Pure knowledge priori that with which no empirical element mixed up. For example, the proposition, " Every change has cause," proposition priori, but impure, because change conception which can only he derived from expe rience.
II. The nuMAX intellect, even in an unfhilosofhical STATE, IS IN POSSESSION OF CERTAIN COGNITIONS PRIORI.
The question now as to criterion, by which we may
securely distinguish pure from an empirical cognition. Ex perience no doubt teaches us that this or that object con stituted in such and such manner, but not that could not possibly exist otherwise. Now, in the first place, we have
proposition which contains the idea of necessity in its very conception, judgment priori moreover, not derived from any other proposition, unless from one equally involving the idea of necessity, absolutely priori. Se condly, an empirical judgment never exhibits strict and abso lute, but only assumed and comparative universality (by in duction) therefore, the most we can say --so far as we have hitherto observed, there
rule. If, on the other hand, and absolute universality, that
no exception to this or that judgment carries with strict
admits of no possible excep
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tion, it is not derived from experience, but is valid absolutely a priori.
Empirical universality is, therefore, only an arbitrary ex tension of validity, from that which may be predicated of a proposition valid in most cases, to that which is asserted of a proposition which holds good in all ; as, for example, in the affirmation, " all bodies are heavy. '
strict universality characterizes a judgment, it necessarily indicates another peculiar source of knowledge, namely, a faculty of cognition <i priori. Necessity and strict univer sality, therefore, are infallible tests for distinguishing pure from empirical knowledge, and are inseparably connected with each other. But as in the use of these criteria the empirical limitation is sometimes more easily detected than the contingency of the judgment, or the unlimited universality which we attach to a judgment is often a more convincing proof than its necessity, it may be advisable to use the criteria separately, each being by itself infallible.
? Now, that in the sphere of human cognition, we have judgments which are necessary, and in the strictest sense universal, consequently pure ii priori, it will be an easy matter to shew. If we desire an example from the sciences,
we need only take any proposition in mathematics. If
we cast our eyes upon the commonest operations of the un
derstanding, the proposition, " every change must have a cause," will amply serve our purpose. In the latter case, indeed, the conception of a cause so plainly involves the con ception of a necessity of connexion with an effect, and of a strict universality of the law, that the very notion of a cause would entirely disappear, were we to derive like Hume, from frequent association of what happens with that which precedes, and the habit thence originating of connecting re presentations --the necessity inherent in the judgment being therefore merely subjective. Besides, without seeking for such examples of principles existing priori in cognition, we might easily shew that such principles are the indispen sable basis of the possibility of experience itself, and con sequently prove their existence priori. For whence could our experience itself acquire certainty, all the rules on which
depends were themselves empirical, and consequently for tuitous No one, therefore, can admit the validity of the use
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of sucb rules as first principles. But, for the present, we may content ourselves with having established the fact, that we do possess and exercise a faculty of pure a priori cog nition ; and, secondly, with having pointed out the proper teats of such cognition, namely, universality and necessity.
Not only in judgments, however, hut even in conceptions, is an A priori origin manifest. For example, if we take away by degrees from our conceptions of a body all that can be referred to mere sensuous experience--colour, hardness or eoftness, weight, even impenetrability -- the body will then vanish ; but the space which it occupied still remains, and this it is utterly impossible to annihilate in thought. Again, if we take away, in like manner, from our empirical conception
of any object, corporeal or incorporeal, all properties which mere experience has taught us to connect with still we cannot think away those through which we cogitate as substance, or adhering to substance, although our conception of substance more determined than that of an object. Compelled, therefore, by that necessity with which the con ception of substance forces itself upon us, we must confess that has its seat in our faculty of cognition priori.
III. PniLOSOPHY STANDS IN NEED OF A SCIENCE WHICH SHALL DETERMINE THE POSSIBILITY, PRINCIPLES, AND EXTENT OF HUMAN KNOWLEDGE PRIORI.
Of far more importance than all that has been above said, the consideration that certain of our cognitions rise com
pletely above the sphere of all possible experience, and by means of conceptions, to which there exists in the whole ex tent of experience no corresponding object, seem to extend the range of our jndgments beyond its bounds. And just in this transcendental or supersensible sphere, where experience affords us neither instruction nor guidance, lie die investi gations of Reason, which, on account of their importance, we consider far preferable to, and as having far more elevated aim than, all that the understanding can achieve within the sphere of sensuous phenomena. So high value do we set upon these investigations, that even at the risk of error, we persist in following them out, and permit neither doubt nor disregard nor indifference to restrain us from the pur suit. These unavoidable problems of mere pure reason are
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God, Freedom (of will) and Immortality. The science which, with all its preliminaries, has for its especial object the solution of these problems is named metaphysics, --a science which is at the very outset dogmatical, that con fidently takes upon itself the execution of this task without
any previous investigation of the ability or inability of reason for such an undertaking.
Now the safe ground of experience being thus abandoned, seems nevertheless natural thst we should hesitate to erect building with the cognitions we possess, without knowing whence they come, and on the strength of principles, the origin of whirh undiscovered. Instead of thus trying to build without foundation, rather to be expected that
we should long ago have put the question, how the under
can arrive at these priori cognitions, and what the extent, validity, and worth which they may possess We say, this natural enough, meaning by the word natural, that which consistent with just and reasonable way of think ing but we understand by the term, that which usually happens, nothing indeed could be mere natural and more
some evident contradiction, we hurry on undoubtingly in our course. This, however, may be avoided, we are suffi ciently cautious in the construction of our fictions, which are not the less fictions on that account.
Mathematical science affords us brilliant example, how far, independently of all experience, we may carry our priori knowledge. true that the mathematician occupies himself with objects and cognitions only in so far as they can be represented by means of intuition. But this circumstance
easily overlooked, because the said intuition can itself be given priori, and therefore hardly to be distinguished from mere pure conception. Deceived such proof of
? standing
than that this investigation should be left
comprehensible
long unattempted. For one part of our pure knowledge, the science of mathematics, has been long firmly estab lished, and thus leads us to form flattering expectations with regard to others, though these may be of quite different nature. Besides, when we get beyond the bounds of ex perience, we are of course safe from opposition in that quarter and the charm of widening the range of our know ledge so great, that unless we are brought to stand-still
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IKTBODUCTIOIT.
the power of reason, we can perceive no limits to the ex tension of our knowledge. The light dove cleaving in free flight the thin air, whose resistance it feels, might imagine that her movements would he far more free and rapid in air less space. Just in the same way did Plato, abandoning the world of sense because of the narrow limits it sets to the understanding, venture upon the wings of ideas beyond into the void space of pure intellect. He did not reflect that he made no real progress by all his efforts for he met with no resistance which might serve him for support, as were, whereon to rest, and on which he might apply his powers, in order to let the intellect acquire momentum for its progress.
indeed, the common fate of human reason in speculation, to finish the imposing edifice of thought as rapidly as possible, and then for the first time to begin to examine whether the foundation solid one or no. Arrived at this point, all sorts of excuses are sought after, in order to console us for its want of stability, or rather indeed, to enable us to dispense
altogether with so late and dangerous an investigation. But what frees us during the process of building from all appre hension or suspicion, and flatters us into the belief of its solidity, this. great part, perhaps the greatest part, of the business of our reason consists in the analyxation of the
which we already possess of objects. By this means we gain multitude of cognitions, which although really nothing more than elucidations or explanations of that which (though in confused manner) was already thought in our conceptions, are, at least in respect of their form, prized as new introspections whilst, so far as regards their matter or content, we have really made no addition to our con ceptions, but only disinvolved them. But as this process does furnish r? al priori knowledge,* which has sure progress and useful results, reason, deceived this, slips in, without being itself aware of assertions of quite different kind; in which, to given conceptions adds others, priori in deed, but entirely foreign to them, without our knowing how
arrives at these, and, indeed, without such question ever suggesting itself. shall therefore at once proceed to examine the difference between these two modes of knowledge.
Not ivnthetical. -- Tr.
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IV. Or TnE DTFFEHENCE BETWEEN ANALYTICAL AND 6TNTUETICAL JUDGMENTS.
In all judgments wherein the relation of a subject to the pre
dicate is cogitated, (I mention affirmative judgments only
here ; the application to negative will be very easy,) this rela
tion is possible in two different ways. Either the predicate
B belongs to the subject A, as somewhat which is contained
(though covertly) in the conception A ; or the predicate B
lies completely out of the conception A, although it stands in connexion with it. In the first instance, I term the judgment
analytical, in the second, synthetical. Analytical judgments
are therefore those in which the connection of the predicate with the subject is cogitated through identity ; those in which this connexion is cogitated without identity, are called synthetical judgments. The former may be called explicative, the latter augmentative* judgments ; because the former add in the predicate nothing to the conception of the subject, but only analyse it into its constituent conceptions, which were thought already in the subject, although in a con fused manner ; the latter add to our conceptions of the subject a predicate which was not contained in and which no analysis could ever have discovered therein. For example, when say, "all bodies are extended," this an analytical judgment. For need not go beyond the conception of body
order to find extension connected with but merely analyse the conception, that is, become conscious of the manifold properties which think in that conception, in order to discover this predicate in therefore an ana lytical judgment. On the other hand, when say, " all bodies are heavy," the predicate something totally different from that which think in the mere conception of
By the addition of such predicate therefore, becomes synthetical judgment.
Judgments of experience, as such, are always synthetical. For would be absurd to think of grounding an analytical
judgment on experience, because in forming such judg ment, need not go out of the sphere of my conceptions,
That is, judgments which reahy add to, and do not merely analy
or explain the conceptions which make up the torn of our knowledge. 7V.
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and therefore recourse"to the testimony of experience is quite unnecessary. That bodies are extended" is not an em pirical judgment, but a proposition which stands firm ft priori. For before addressing myself to experience, I already have in my conception all the requisite conditions for the judg ment, and I have only to extract the predicate from the concep tion, according to the principle of contradiction, and thereby at the same time become conscious of the necessity of the judgment, a necessity which I could never learn from ex
On the other hand, though at first I do not at all
perience.
include the predicate of weight in my conception of body in general, that, conception still indicates an object of ex
? perience, a part of the totality of experience, to which I can still add other parts ; and this I do when I recognize by ob servation that bodies are heavy. I can cognize beforehand by analysis the conception of body through the character istics of extension, impenetrability, shape, &c, all which are cogitated in this conception. But now I extend my know ledge, and looking back on experience from which I had derived this conception of body, I find weight at all times connected with the above chsracteristics, and therefore I synthetically add to my conceptions this as a predicate, and say, " all bodies are heavy. " Thus it is experience upon which rests the possibility of the synthesis of the predicate of weight with the conception of body, because both con ceptions, although the one is not contained in the other, still belong to one another (only contingently, however), as parts of a whole, namely, of experience, which is itself a synthesis of intuitions.
But to synthetical judgments a priori, such aid is entirely wanting. If I go out of and beyond the conception A, in order to recognize another B as connected with what foundation have to rest on, whereby to render the synthesis possible have here no longer the advantage of looking out in the sphere of experience for what want. Let us
take, for example, the proposition, "everything that happens has cause. " In the conception of something that happens, indeed think an existence which certnin time antecedes,
and from this can derive analytical judgments. But the conception of cause lies quite out of the above " conception, tad indicates something entirely different from that which
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9
happens," and is consequently not contained in that con ception. How then am I able to assert concerning the general conception -- "that which happens " -- something entirely dif ferent from that conception, and to recognize the conception of cause although not contained in yet as belonging to and even necessarily? what here the unknown = upon which the understanding rests when believes has found, out of the conception foreign predicate which nevertheless considers to be connected with cannot be experience, because the principle adduced annexes the two represent ations, cause and effect, to the representation existence, not only with universality, which experience cannot give, but also with the expression of necessity, therefore completely prion and from pure conceptions. Upon such synthetical, that augmentative propositions, depends the whole aim of our specu lative knowledge priori for although analytical
? judgments are indeed highly important and necessary, they are so, only
to arrive at that clearness of conceptions which requisite for sure and extended synthesis, and this alone real acquisition.
V. In all theobetical sciences of season, synthetical JUDGMENTS PRIORI ABB CONTAINED AS PBISCIPLES.
Matiiematicax judgments are always synthetical. Hitherto this fact, though incontestibly true and very important in its consequences, seems to have escaped the analysts of the human mind, nay, to be in complete opposition to all their conj'c tures. For as was found that mathematical conclusions all
proceed according to the principle of contradiction (whi<. h the nature of every apodeictic certainty requires), people became persuaded that the fundamental principles of the science also were recognised and admitted in the same way. But the notion fallacious for although synthetical pro position can certainly be discerned by means of the principle of contradiction, this possible only when another syntheti cal proposition precedes, from which the latter deduced, but never of itself.
Before all, be observed, that proper mathematical propo
sitions are always judgments priori, and not empirical, be cause they carry nlong with them the conception of necessity,
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which cannot be given by experience. If this be demurred to, it matters not ; I will then limit my assertion to pure ma thematics, the very conception of which implies, that it con sists of knowledge altogether non-empirical and a priori.
We might, indeed, at first suppose that the proposition 7 + 5=12, is a merely analytical proposition, following (ac cording to the principle of contradiction), from the concep tion of a sum of seven and five. But if we regard it more narrowly, we find that our conception of the sum of seven and five contains nothing more than the uniting of both sums into one, whereby it cannot at all be cogitated what this single number is which embraces both. The conception of twelve is by no means obtained by merely cogitating the union of seven and five ; and we may analyze our conception of such a possible sum as long as we will, still we shall never dis cover in it the notion of twelve. We must go beyond these conceptions, and have recourse to an intuition which corresponds to one of the two,--our five fingers, for ex ample, or like Segner in his "Arithmetic," five points, and so by degrees, add the units contained in the five given in the intuition, to the conception of seven. For I first take the number 7, and, for the conception of 5 calling in the aid of the fingers of my hand as objects of intuition, I add the units, which I before took together to make up the number
5, gradually now by means of the material image my hand, to the number 7, and by this process, I at length see the number 12 arise. That 7 should be added to 5, I have ceriainly cogitated in my conception of a sum=7-r5, but not that this sum was equal to 12. Arithmetical propositions are therefore always synthetical, of which we may become more clearly convinced by trying large numbers. For it wih thus become quite evident, that turn and twist our conceptions as we may, it is impossible, without having recourse to intui tion, to arrive at the sum total or product by means of the mere analysis of our conceptions. Just as little is any princi ple of pure geometry analytical. " A straight line between
two points is the shortest," is a synthetical proposition. For my conception of straight, contains no notion of quantity, but is merely qualitative. The conception of the shortest is therefore wholly an addition, and by no analysis can it be ex tracted from our conception of a straight line. Intuition
? ? ? ? SYNTHETICAL JUDGMENTS A PRIORI.
11
mast therefore here lend its aid, by means of which and thai only, our synthesis is possible.
Some few principles preposited by geometricians are, in deed, really analytical, and depend on the principle of con tradiction. They serve, however, like identical propositions, as links in the chain of method, not as principles, -- for ex ample, a=a, the whole is equal to itself, or (a+6) 7 a, the whole is greater than its part. And yet even these principles themselves, though they derive their validity from pure conceptions, are only admitted in mathematics because they can be presented in intuition. What causes us here
to believe that the predicate of such apodeictic judgments is already contained in our conception, and that
the judgment is therefore analytical, is merely the equivocal nature of the expression. We must join in thought a certain predicate to a given conception, and this necessity cleaves already to the conception. But the question not what we must join in thought to the given conception, but what we really think therein, though only obscurely, and then becomes manifest, that the predicate pertains to these conceptions, ne cessarily indeed, yet not as thought in the conception itself, out by virtue of an intuition, which must be added to the con ception.
2. The science of Natural Philosophy (Physics) contains in itself synthetical judgments priori, as principles. shall adduce two propositions. For instance, the proposition, " in all changes of the material world, the quantity of matter remains unchanged or, that, " in all communication of motion, action and re-action must always be equal. " In both of these, not only the necessity, and therefore their origin priori clear, but also that they are synthetical propo sitions. For in the conception of matter, do not cogitate
its permanency, but merely its presence in space, which fills. therefore really go out of and beyond the conception of matter, in order to think on to something priori, which did not think in it. The proposition therefore not analyti cal, but synthetical, and nevertheless conceived priori and so with regard to th<< other propositions of the pure part of natural philosophy.
3. As to Metaphysics, even we look upon merely as an attempted science, yet, from the nature of human reason, an
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indispensable one, we find that it must contain synthetical propositions & priori. It is not merely the duty of meta physics to dissect, and thereby analytically to illustrate the conceptions which we form a priori of things ; but we seek tc widen the range of our & priori knowledge. For this purpose, we must avail ourselves of such principles as add something tc the original conception --something not identical with, nor contained in and by means of synthetical judgments
priori, leave far behind us the limits of experience for example, in the proposition, " the world must have begin ning," and such like. Thus metaphysics, according to the proper aim of the science, consists merely of synthetical pro positions priori.
VI. The umrEB8AL problem of puee reasox.
? It extremely advantageous to be able to bring number of investigations under the formula of single problem. For in this manner, we not only facilitate our own labour, inas much as we define clearly to ourselves, but also render more easy for others to decide whether we have done justice to our undertaking. The proper problem of pure reason, then,
contained in the question, " How are synthetical judgments priori possible ? "
That metaphysical science has hitherto remained so va cillating state of uncertainty and contradiction, only to be attributed to the fact, that this great problem, and perhaps even the difference between analytical and synthetical judg ments, did not sooner suggest itself to philosophers. Upon the solution of this problem, or upon sufficient proof of the im possibility of synthetical knowledge priori, depends the existence or downfall of the science of metaphysics. Among
David Hume came the nearest of all to this problem yet never acquired in his mind sufficient preci sion, nor did he regard the question in its universality. On the contrary, he stopped short at the synthetical proposition ol the connection of an effect with its cause. , (principium causal- itatis), insisting that such proposition priori was impos sible. According to his conclusions, then, all that we term
philosophers,
science fancied insight of reason
metaphysical
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? THE GHA1TD PBOBLEM OF PtfBE EEABOif. 13
of necessity. Against this assertion, destructive to all pure philosophy, he would have been guarded, had he had our problem before his eyes in its universality. For he would then have perceived that, according to his own argument, there likewise could not be any pure mathematical science, which assuredly cannot exist without synthetical propositions d priori, -- an absurdity from which his good understanding must have saved him.
In the solution of the above problem is at the same time comprehended the possibility of the use of pure reason in the foundation and construction of all sciences which contain theoretical knowledge & priori of objects, that is to say, the answer to the following questions :
? How is pure mathematical science possible ?
How is pure natural science possible ?
Respecting these sciences, as they do certainly exist, it may
with propriety be asked, how they are possible ? --for that they must be possible, is shewn by the fact of their really existing. * But as to metaphysics, the miserable progress it has hitherto made, and the fact that of no one system yet brought forward, as far as regards its true aim, can it be said that this science really exists, leaves any one at liberty to doubt with reason the very possibility of its existence.
Yet, in a certain sense,' this kind of knowledge must un questionably be looked upon as given; in other words, meta physics must be considered as really existing, if not as a science, nevertheless as a natural disposition of the human mind (metaphyska naturalis). For human reason, without any instigations imputable to the mere vanity of great know ledge, unceasingly progresses, urged on by its own feeling of need, towards such questions as cannot be answered by any em pirical application of reason, or principles derived therefrom ; and so there has ever really existed in every man some system
* As to the existence of pure natural science, or physics, perhaps many may still express doubts. But we have only to look at the different pro positions which are commonly treated of at the commencement of proper (empirical) physical science --those, for example, relating to the perma nence of the same quautity of matter, the vit inertia, the equality of action and reaction. &c. --to be soou convinced that ttiey form e science of pure physics {phyrica pur a, or rationalis), which well deserves to ha separately exposed as a special science, in its whole extent, whether thai be (rr<<n' or confined.
? ? ? u INTBODtJCTIOlT.
of metaphysics. It will always exist, so soon as reason awake* to the exercise of its power of speculation. And now the question arises -- How is metaphysics, as a natural disposition, possible ? In other words, how, from the nature of universal human reason, do those questions arise which pure reason proposes to itself, and which it is impelled by its own feeling
af need to answer as well as it can ?
But as in all the attempts hitherto made to answer the ques
tions which reason is prompted by its very nature to propose to itself, for example, whether the world had a beginning, or has existed from eternity, it has always met with unavoidable contradictions, we must not rest satisfied with the mere natu ral disposition of the mind to metaphysics, that with the existence of the faculty of pure reason, whence, indeed, some sort of metaphysical system always arises; but must be possible to arrive at certainty in regard to the question whether we know or do not know the things of which metaphysics treats. We must be able to arrive at decision on the subjects of its questions, or on the ability or inability of reason to form'
any judgment respecting them and therefore either to extend with confidence the bounds of our pure reason, or to set strictly defined and safe limits to its action. This last ques tion, which arises out of the above universal problem, would properly run thus How metaphysics possible as science
Thus, the critique of reason leads at last, naturally and necessarily, to science and, on the other hand, the dogma tical use of reason without criticism leads to groundless asser tions, against which others equally specious can always be set, thus ending unavoidably in scepticism.
Besides, this science cannot be of great and formidable prolixity, because has not to do with objects of reason, the variety of which inexhaustible, but merely with reason her self and her problems problems whieh arise out of her own bosom, and are not proposed to her the nature of outward 'things, but her own nature. And when once reason has previously become able completely to understand her own
power in regard to objects which she meets with in experience, will be easy to determine securely the extent and limits of
her attempted application to objects beyond the confines
? experience. mini, therefore, We may anJ
regard
the hitherto attempts
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made; to establish metaphysical science dogmatically as non existent. For what of analysis, that mere dissection of
contained in one or other, not the aim of, but only preparation for metaphysics proper, which has for its object the extension, by means of synthesis, of our a priori knowledge. And for this purpose, mere analysis of course useless, because only shews what contained in these conceptions, but not how we arrive, a priori, at them; and this her duty to shew, in order to be able afterwards to determine their valid use in regard to all objects of expe rience, to all knowledge general. But little self-denial, indeed, needed to give up these pretensions, seeing the undeniable, and in the dogmatic mode of procedure, in evitable contradictions of Reason with herself, have long since ruined the reputation of every system of metaphysics that has appeared up to this time. will require more firmness to remain undeterred by difficulty from within, and opposition from without, from endeavouring, method quite opposed to all those hitherto followed, to further the growth and fruitfulness of science indispensable to human reason -- science from which every branch has borne may be cut away, but whose roots remain indestructible.
VII. Idea and division of a pabticitlab science, ttnden THE NAME OF A CRITIQUE OF PuBE REASON.
From all that has been said, there results the idea of par ticular science, which may be called the Critique of Pvre Reason. For reason the faculty which furnishes us with the principles of knowledge priori. Hence, pure reason
the faculty which contains the principles of cognizing any thing absolutely priori. An Organon of pure reason would be a compendium of those principles according to which alone all pure cognitions priori can be obtained. The completely extended application of such an organon would afford us system of pure reason. As this, however, de manding great deal, and yet doubtful whether any extension of our knowledge be here possible, or so, in what cases we can regard science of the mere criticism of pure reason, its sources and limits, as the propcedeutie to ? yBtem of pure reason. Such science must not be called Doctrine, but only Criticie of pure Reason and iu use,
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? l<< INTRODUCTION
in regard to speculation, would be only negative, hot to en large the bounds of, but to purify our reason, and to shield it against error, --which alone is no little gain. I apply the term transcendental to all knowledge which is not so much occu pied with objects as with the mode of our cognition of these objects, so far as this mode of cognition is possible a priori. A system of such conceptions would be called Transcendental Philosophy. But this, again, is still beyond the bounds of our present essay. For as such a science must contain a complete exposition not only of our synthetical a priori, but of our analytical & priori knowledge, it is of too wide a range for our present purpose, because we do not require to carry our analysis any farther than is necessary to understand, in their full extent, the principles of synthesis a priori, with which alone we have to do. This investigation, which we cannot properly call a doctrine, but only a transcendental critique, because it aims not at the enlargement, but at the correction and guidance of our knowledge, and is to serve as a touchstone of the worth or worthlessness of all know ledge a priori, is the sole object of our present essay. Such a critique is consequently, as far as possible, a preparation for an organon ; and if this new organon should be found to fail, at least for a canon of pure reason, according to which the complete system of the philosophy of pure reason, whether it extend or limit the bounds of that reason, might one day be set forth both analytically and synthetically. For that this is possible, nay, that such a system is not of so great extent as to preclude the hope of its ever being com
is evident. For we have not here to do with the nature of outward objects, which is infinite, but solely with the mind, which judges of the nature of objects, and, again, with the mind only in respect of its cognition & priori. And the object of our investigations, as it is not to be sought without, but altogether within ourselves, cannot remain con cealed, and in all probability is limited enough to be com pletely surveyed and fairly estimated, according to its worth or worthlessness. Still less let the reader here expect a critique of books and systems of pure reason ; our present object is exclusively a critique of the faculty of pure reason itself. Only when we make this critique our foundation, do we possess a pure touchstone for estimating the philosophical
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? ? ? IDEA OF A UKITMiDl
OF PUKE HEA. SOIT. 17
value of ancient and modern writings on this subject; and without this criterion, the incompetent historian or judge decides upon and corrects the groundless assertions of others with his own, which have themselves just as little foundation.
Transcendental philosophy is the idea of a science, for
which the Critique of Pure Reason must sketch the whole
plan architectonically, that from principles, with full
guarantee for the validity and stability of all the parts which
enter into the building. the system of all the principles
of pure reason. If this Critique itself does not assume the
title of transcendental philosophy, only because, to be
complete system, ought to contain full analysis of all
human knowledge a priori. Our critique must, indeed, lay
before us complete enumeration of all the radical concep
tions which constitute the said pure knowledge.
