The Online Library of Liberty

A project of Liberty Fund, Inc.

• Dedication
• Preface 1
• Translator’s Preface
• Translator’s Preface to Second Edition
• Introduction [p. 1]
• I: The Idea of Transcendental Philosophy
• II: Division of Transcendental Philosophy
• I: The Elements of Transcendentalism
• Part I: Transcendental Æsthetic [p. 19]
• Section I: Of Space
• Section II: Of Time
• Part II: Transcendental Logic [p. 50]
• Introduction the Idea of a Transcendental Logic
• I: Of Logic In General
• II: Of Transcendental Logic
• III: Of the Division of General Logic Into Analytic and Dialectic
• IV: Of the Division of Transcendental Logic Into Transcendental Analytic and Dialectic
• Division I: Transcendental Analytic In Two Books, With Their Chapters and Sections
• Book I: Analytic of Concepts
• Chapter I: Method of Discovering All Pure Concepts of the Understanding
• Section I: Of the Logical Use of the Understanding In General
• Section II: Of the Logical Function of the Understanding In Judgments [p. 70]
• Section III: Of the Pure Concepts of the Understanding, Or of the Categories
• Chapter II: Of the Deduction of the Pure Concepts of the Understanding [p. 84]
• Section I: Of the Principles of a Transcendental Deduction In General
• Section II: Of the a Priori Grounds For the Possibility of Experience
• I: Of the Synthesis of Apprehension In Intuition
• II: Of the Synthesis of Reproduction In Imagination
• III: Of the Synthesis of Recognition In Concepts [p. 103]
• IV: Preliminary Explanation of the Possibility of the Categories As Knowledge a Priori
• Section III: Of the Relation of the Understanding to Objects In General, and the Possibility of Knowing Them a Priori [p. 115]
• Book II: Analytic of Principles
• Introduction of the Transcendental Faculty of Judgment In General
• Chapter I: Of the Schematism of the Pure Concepts of the Understanding [p. 137]
• Chapter II: System of All Principles of the Pure Understanding [p. 148]
• Section I: Of the Highest Principle of All Analytical Judgments
• Section II: Of the Highest Principle of All Synthetical Judgments [p. 154]
• Section III: Systematical Representation of All Synthetical Principles of the Understanding
• I: [of the Axioms of Intuition 1 Principle of the Pure Understanding
• II: [ Anticipations of Perception
• III: [ the Analogies of Experience
• IV: The Postulates of Empirical Thought In General
• Chapter III: On the Ground of Distinction of All Subjects Into Phenomena and Noumena
• I.: Identity and Difference
• II.: Agreement and Opposition
• III.: The Internal and the External
• IV.: Matter and Form
• Note On the Amphiboly of Reflective Concepts
• Division II: Transcendental Dialectic In Two Books, With Their Chapters and Sections [p. 293]
• Introduction: 1.
• Book I: Of the Concepts of Pure Reason [p. 310]
• First Section of Ideas In General
• Second Section of Transcendental Ideas [p. 321]
• Third Section System of Transcendental Ideas [p. 333]
• Book II: Of the Dialectical Conclusions of Pure Reason
• Chapter I: Of the Paralogisms of Pure Reason [p. 341]
• Chapter II: The Antinomy of Pure Reason
• Section I: System of Cosmological Ideas
• Section II: Antithetic of Pure Reason
• Section III: Of the Interest of Reason In These Conflicts [p. 462]
• Section IV: Of the Transcendental Problems of Pure Reason, and the Absolute Necessity of Their Solution
• Section V: Sceptical Representation of the Cosmological Questions In the Four Transcendental Ideas [p. 485]
• Section VI: Transcendental Idealism As the Key to the Solution of Cosmological Dialectic
• Section VII: Critical Decision of the Cosmological Conflict of Reason With Itself
• Section VIII: The Regulative Principle of Pure Reason With Regard to the Cosmological Ideas [p. 508]
• Section IX: Of the Empirical Use of the Regulative Principle of Reason With Regard to All Cosmological Ideas
• Chapter III: The Ideal of Pure Reason
• Section I: Of the Ideal In General
• Section II: Of the Transcendental Ideal ( Prototypon Transcendentale )
• Section III: Of the Arguments of Speculative Reason In Proof of the Existence of a Supreme Being
• Section IV: Of the Impossibility of an Ontological Proof of the Existence of God [p. 592]
• Section V: Of the Impossibility of a Cosmological Proof of the Existence of God [p. 603]
• Section VI: Of the Impossibility of the Physico-theological Proof
• Section VII: Criticism of All Theology Based On Speculative Principles of Reason [p. 631]
• Chapter I: The Discipline of Pure Reason
• Section I: The Discipline of Pure Reason In Its Dogmatical Use
• Section II: The Discipline of Pure Reason In Its Polemical Use
• Section III: The Discipline of Pure Reason With Regard to Hypotheses
• Section IV: The Discipline of Pure Reason With Regard to Its Proofs
• Chapter II: The Canon of Pure Reason [p. 795]
• First Section: of the Ultimate Aim of the Pure Use of Our Reason
• Section II: Of the Ideal of the Summum Bonum As Determining the Ultimate Aim of Pure Reason
• Section III: Of Trowing, Knowing, and Believing [p. 820]
• Chapter III: The Architectonic of Pure Reason [p. 832]
• Chapter IV: The History of Pure Reason [p. 852]
• Supplement I: Motto to Second Edition
• Supplement II: Preface to the Second Edition. 1787. [p. Vii]
• Supplement III: Supplement Iv
• Supplement V
• Supplement Vi
• Supplement V
• Supplement Vi
• Supplement Vii
• Supplement Viii
• Supplement Ix
• Supplement X
• Supplement Xi
• Supplement Xii
• Supplement Xiii
• Supplement Xiv
• Supplement Xv
• Supplement Xvi a
• Supplement Xvi B
• Supplement Xvii
• Supplement Xviii
• Supplement Xix
• Supplement Xx
• Supplement Xxi
• Supplement Xxii
• Supplement Xxiii
• Supplement Xxiv
• Supplement Xxv
• Supplement Xxvi
• Supplement Xxvii
• Supplement Xxviii

Section III

The Discipline of Pure Reason with Regard to Hypotheses

As then the criticism of our reason has at last taught us so much at least, that with its pure and speculative use we can arrive at no knowledge at all, would not this seem to open a wide field for hypotheses, as, where we cannot assert with certainty, we are at all events at liberty to form guesses and opinions?

If the faculty of imagination is not simply to [p. 770] indulge in dreams, but to invent and compose under the strict surveillance of reason, it is necessary that there should always be something perfectly certain, and not only invented or resting on opinion, and that is the possibility of the object itself. If that is once given, it is then allowable, so far as its reality is concerned, to have recourse to opinion, which opinion, however, if it is not to be utterly groundless, must be brought in connection with what is really given and therefore certain, as its ground of explanation. In that case, and in that case only, can we speak of an hypothesis.

As we cannot form the least conception of the possibility of a dynamical connection a priori, and as the categories of the pure understanding are not intended to invent any such connection, but only, when it is given in experience, to understand it, we cannot by means of these categories invent one single object as endowed with a new quality not found in experience, or base any permissible hypothesis on such a quality; otherwise we should be supplying our reason with empty chimeras, and not with concepts of things. Thus it is not permissible to invent any new and original powers, as, for instance, an understanding capable of perceiving objects without the aid of the senses; or a force of attraction without any contact; a new kind of substances that should exist, for instance, in space, without being impenetrable, and consequently, also, any connection of substances, different from that which is supplied by experience; [p. 771] no presence, except in space, no duration, except in time. In one word, our reason can only use the conditions of possible experience as the conditions of the possibility of things; it cannot invent them independently, because such concepts, although not self-contradictory, would always be without an object.

The concepts of reason, as was said before, are mere ideas, and it is true that they have no object corresponding to them in experience; but they do not, for all that, refer to purely imaginary objects, which are supposed to be possible. They are purely problematical, in order to supply (as heuristic fictions) regulative principles for the systematical employment of the understanding in the sphere of experience. If they are not that, they would become mere fictions the possibility of which is quite indemonstrable, and which, therefore, can never be employed as hypotheses for the explanation of real phenomena. It is quite permissible to represent the soul to ourselves as simple, in order, according to this idea, to use the complete and necessary unity of all the faculties of the soul, although we cannot understand it in concreto, as the principle of all our enquiries into its internal phenomena. But to assume the soul as a simple substance (which is a transcendent concept) would be a proposition, not only indemonstrable (this is the case with several physical hypotheses), but purely [p. 772] arbitrary and rash: because the simple can never occur in any experience, and if by substance we understand the permanent object of sensuous intuition, the very possibility of a simple phenomenon is perfectly inconceivable. Reason has no right whatever to assume, as an opinion, purely intelligible beings, or purely intelligible qualities of the objects of the senses; although, on the other side, as we have no concepts whatever, either of their possibility or impossibility, we cannot claim any truer insight enabling us to deny dogmatically their possibility.

In order to explain given phenomena, no other things or reasons can be adduced but those which, according to the already known laws of phenomena, have been put in connection with them. A transcendental hypothesis, adducing a mere idea of reason for the explanation of natural things, would therefore be no explanation at all, because it would really be an attempt at explaining what, according to known empirical principles, we do not understand sufficiently by something which we do not understand at all. Nor would the principle of such an hypothesis serve to help the understanding with regard to its objects, but only to satisfy our reason. Order and design in nature must themselves be explained on natural grounds and according to natural laws; and for this [p. 773] purpose even the wildest hypotheses, if only they are physical, are more tolerable than a hyperphysical one, — that is, the appeal to the Divine Author, who is called in for that very purpose. This would be a principle of ratio ignava, to pass by all causes the objective reality of which, in their possibility at least, may be known by continued experience, in order to rest on a mere idea, which no doubt is very agreeable to our reason. With regard to the absolute totality of the ground of explanation in the series of causes, there can be no difficulty, considering that all mundane objects are nothing but phenomena, in which we can never hope to find absolute completeness in the synthesis of the series of conditions.

It is impossible to allow transcendental hypotheses in the speculative use of reason, or the use of hyperphysical instead of physical explanations; partly, because reason is not in the least advanced in that way, but, on the contrary, cut off from its own proper employment, partly because such a licence would in the end deprive reason of all the fruits that spring from the cultivation of its own proper soil, namely, experience. It is true, no doubt, that whenever the explanation of nature seems difficult to us, we should thus always have a transcendent explanation ready to hand, which relieves us of all investigation; but in that case we are led in the end, not to an [p. 774] understanding, but to a complete incomprehensibility of the principle which, from the very beginning, was so designed that it must contain the concept of something which is the absolutely First.

What is, secondly, required in order to render an hypothesis acceptable, is its adequacy for determining a priori, by means of it, all the consequences that are given. If, for that purpose, we have to call in the aid of supplementary hypotheses, they rouse the suspicion of a mere fiction, because each of them requires for itself the same justification as the fundamental idea, and cannot serve therefore as a sufficient witness. No doubt, if we once admit an absolutely perfect cause, there is no difficulty in accounting for all the order, magnitude, and design which are seen in the world. But if we consider what seem to us at least deviations and evils in nature, new hypotheses will be required in order to save the first hypothesis from the objections which it has to encounter. In the same manner, whenever the simple independence of the human soul, which has been admitted in order to account for all its phenomena, is called into question on account of the difficulties arising from phenomena similar to the changes of matter (growth and decay), new hypotheses have to be called in, which may seem plausible, but possess no authority, except what they derive from the opinion [p. 775] which was to yield the chief explanation, and which they themselves were called upon to defend.

If the two hypotheses which we have just mentioned as examples of the assertions of reason (the incorporeal unity of the soul, and the existence of a Supreme Being) are to be accepted, not as hypotheses, but as dogmas proved a priori, we have nothing to say to them. Great care, however, should be taken in that case that they should be proved with the apodictic certainty of a demonstration. It would be as absurd to try to make the reality of such ideas plausible only, as to try to make a geometrical proposition plausible. Reason, independent of all experience, knows everything either a priori, and as necessary, or not at all. Its judgment, therefore, is never opinion, but either an abstaining from all judgments, or apodictic certainty. Opinions and guesses as to what belongs to things can be admitted in explanation only of what is really given, or as resulting, according to empirical laws, from something that is really given. They belong, therefore, to the series of the objects of experience only. Outside that field to opine is the same as to play with thoughts, unless we suppose that even a doubtful and uncertain way of judging might lead us perhaps on to the truth.

But although, when dealing with the purely [p. 776] speculative questions of pure reason, no hypotheses are admissible in order to found on them any propositions, they are perfectly admissible in order, if possible, to defend them; that is to say, they may be used for polemical, but not for dogmatical purposes. Nor do I understand by defending the strengthening of the proofs in support of our assertions, but only the refutation of the dialectical arguments of the opponent which are intended to invalidate our assertions. All synthetical propositions of pure reason have this peculiarity that, although the philosopher who maintains the reality of certain ideas never possesses sufficient knowledge in order to render his own propositions certain, his opponent is equally unable to prove the opposite. It is true, no doubt, that this equality of fortune, which is peculiar to human reason, favours neither of the two parties with regard to their speculative knowledge, and hence the never-ending feuds in this arena. But we shall see nevertheless that, in relation to its practical employment, reason has the right of admitting what, in the sphere of pure speculation, it would not be allowed to admit without sufficient proof. Such admissions, no doubt, detract from the perfection of speculation, but practical interests take no account of this. Here, therefore, reason is in possession, without having to prove the legitimacy of its title, which, indeed, it would be [p. 777] difficult to do. The burden of proof rests, therefore, on the opponent; and as he knows as little of the point in question, to enable him to prove its non-existence, as the other who maintains its reality, it is evident that there is an advantage on the side of him who maintains something as a practically necessary supposition (melior est conditio possidentis). He is clearly entitled, as it were in self-defence, to use the same weapons in support of his own good cause, which the opponent uses against it, that is, to employ hypotheses, which are not intended to strengthen the arguments in favour of his own view, but only to show that the opponent knows far too little of the subject under discussion to flatter himself that he possesses any advantage over us, so far as speculative insight is concerned.

In the field of pure reason, therefore, hypotheses are admitted as weapons of defence only, not in order to establish a right, but simply in order to defend it; and it is our duty at all times to look for a real opponent within ourselves. Speculative reason in its transcendental employment is by its very nature dialectical. The objections which we have to fear lie in ourselves. We must look for them as we look for old, but never superannuated claims, if we wish to destroy them, and thus to establish a permanent peace. External tranquillity is a mere illusion. It is necessary to root up the very germ of these objections which lies in the nature of human reason; and how can we root it up, unless we allow it freedom, nay, [p. 778] offer it nourishment, so that it may send out shoots, and thus discover itself to our eyes, so that we may afterwards destroy it with its very root? Try yourselves therefore to discover objections of which no opponent has ever thought; nay, lend him your weapons, and grant him the most favourable position which he could wish for. You have nothing to fear in all this, but much to hope for, namely, that you may gain a possession which no one will ever again venture to contest.

In order to be completely equipped you require the hypotheses of pure reason also, which, although but leaden weapons (because not steeled by any law of experience), are yet quite as strong as those which any opponent is likely to use against you. If, therefore (for any not speculative reason), you have admitted the immaterial nature of the soul, which is not subject to any corporeal changes, and you are met by the difficulty that nevertheless experience seems to prove both the elevation and the decay of our mental faculties as different modifications of our organs, you can weaken the force of this objection by saying that you look upon the body as a fundamental phenomenon only, which, in our present state (in this life), forms the condition of all the faculties of our sensibility, and hence of our thought. In that case the separation from the body would be the end of the sensuous employment and the beginning of the intelligible employment of our faculty of knowledge. The body would thus have to be [p. 779] considered, not as the cause of our thinking, but only as a restrictive condition of it, and, therefore, if on one side as a support of our sensuous and animal life, on the other, all the more, as an impediment of our pure and spiritual life, so that the dependence of the animal life on the constitution of the body would in no wise prove the dependence of our whole life on the state of our organs. You may go even further and discover new doubts which have either not been raised at all before, or at all events have not been carried far enough.

Generation in the human race, as well as among irrational creatures, depends on so many accidents, on occasion, on sufficient sustenance, on the views and whims of government, nay, even on vice, that it is difficult to believe in the eternal existence of a being whose life has first begun under circumstances so trivial, and so entirely dependent on our own choice. As regards the continuance (here on earth) of the whole race, there is less difficulty, because the accidents in individual cases are subject nevertheless to a rule with regard to the whole. With regard to each individual, however, to expect so important an effect from such insignificant causes seems very strange. But even against this you may adduce the following transcendental hypothesis, namely, that all life is really intelligible only, not subject to the changes of time, and neither [p. 780] beginning in birth, nor ending in death. You may say that this life is phenomenal only, that is, a sensuous representation of the pure spiritual life, and that the whole world of sense is but an image passing before our present mode of knowledge, but, like a dream, without any objective reality in itself; nay, that if we could see ourselves and other objects also as they really are, we should see ourselves in a world of spiritual natures, our community with which did neither begin at our birth nor will end with the death of the body, both being purely phenomenal.

Although it is true that we do not know anything about what we have here been pleading hypothetically against our opponents, and that we ourselves do not even seriously maintain it, it being simply an idea invented for self-defence and not even an idea of reason, yet we are acting throughout quite rationally. In answer to our opponent who imagines that he has exhausted all possibilities, and who wrongly represents the absence of empirical conditions as a proof of the total impossibility of our own belief, we are simply showing him that he can no more, by mere laws of experience, comprehend the whole field of possible things by themselves than we are able, outside of experience, to establish anything for our reason on a really secure foundation. Because we bring forward such hypothetical defences against the pretensions of our boldly denying opponent, we must not be supposed to have [p. 781] adopted these opinions as our own. We abandon them so soon as we have disposed of the dogmatical conceit of our opponent. It seems no doubt very modest and moderate to maintain a simple negative position with regard to the assertions of other people; but to attempt to represent objections as proofs of the opposite opinion is quite as arrogant as to assume the position of the affirming party and its opinions.

It is easy to see, therefore, that in the speculative employment of reason hypotheses are of no value by themselves, but relatively only, as opposed to the transcendental pretensions of the opposite party. For to extend the principles of possible experience to the possibility of things in general is quite as transcendent as to ascribe objective reality to concepts which cannot have an object except outside the limits of all possible experience. The assertory judgments of pure reason must (like everything known by reason) be either necessary or nothing at all. Reason, in fact, knows of no opinions. The hypotheses, however, which we have just been discussing are problematical judgments only, which, at least, cannot be refuted, though they can neither be proved by anything. They are nothing but private1 opinions, but (for our own satisfaction) [p. 782] we cannot well do without them to counteract misgivings that may arise in our minds. In this character they should be maintained, but we must take great care less they should assume independent authority and a certain absolute validity, and drown our reason beneath fictions and phantoms.

[1 ]Read reine instead of keine.