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

First Section

Of Ideas in General

In spite of the great wealth of our languages, a thoughtful mind is often at a loss for an expression that should square exactly with its concept; and for want of which he cannot make himself altogether intelligible, either to others or to himself. To coin new words is to arrogate to oneself legislative power in matters of language, a proceeding which seldom succeeds, so that, before taking so desperate a step, it is always advisable to look about, in dead and learned languages, whether they do not contain such a concept and its adequate expression. Even if it should happen that the original meaning of the word had become somewhat uncertain, through carelessness on the part of its authors, it is better nevertheless to determine and fix the meaning which principally belonged to it (even if it should remain doubtful whether it was originally used exactly in that meaning), than to spoil our labour by becoming unintelligible.

Whenever therefore there exists one single word only for a certain concept, which, in its received meaning, exactly covers that concept, and when it is of [p. 313] great consequence to keep that concept distinct from other related concepts, we ought not to be lavish in using it nor employ it, for the sake of variety only, as a synonyme in the place of others, but carefully preserve its own peculiar meaning, as otherwise it may easily happen that the expression ceases to attract special attention, and loses itself in a crowd of other words of very different import, so that the thought, which that expression alone could have preserved, is lost with it.

From the way in which Plato uses the term idea, it is easy to see that he meant by it something which not only was never borrowed from the senses, but which even far transcends the concepts of the understanding, with which Aristotle occupied himself, there being nothing in experience corresponding to the ideas. With him the ideas are archetypes of things themselves, not only, like the categories, keys to possible experiences. According to his opinion they flowed out from the highest reason, which however exists no longer in its original state, but has to recall, with difficulty, the old but now very obscure ideas, which it does by means of reminiscence, commonly called philosophy. I shall not enter here on any literary discussions in order to determine the exact meaning which the sublime philosopher himself connected with that expression. I shall only remark, that it is by no [p. 314] means unusual, in ordinary conversations, as well as in written works, that by carefully comparing the thoughts uttered by an author on his own subject, we succeed in understanding him better than he understood himself, because he did not sufficiently define his concept, and thus not only spoke, but sometimes even thought, in opposition to his own intentions.

Plato knew very well that our faculty of knowledge was filled with a much higher craving than merely to spell out phenomena according to a synthetical unity, and thus to read and understand them as experience. He knew that our reason, if left to itself, tries to soar up to knowledge to which no object that experience may give can ever correspond; but which nevertheless is real, and by no means a mere cobweb of the brain.

Plato discovered his ideas principally in what is practical,1 that is, in what depends on freedom, which again belongs to a class of knowledge which is a [p. 315] peculiar product of reason. He who would derive the concept of virtue from experience, and would change what at best could only serve as an example or an imperfect illustration, into a type and a source of knowledge (as many have really done), would indeed transform virtue into an equivocal phantom, changing according to times and circumstances, and utterly useless to serve as a rule. Everybody can surely perceive that, when a person is held up to us as a model of virtue, we have always in our own mind the true original with which we compare this so-called model, and estimate it accordingly. The true original is the idea of virtue, in regard to which all possible objects of experience may serve as examples (proofs of the practicability, in a certain degree, of that which is required by the concept of reason), but never as archetypes. That no man can ever act up to the pure idea of virtue does not in the least prove the chimerical nature of that concept; for every judgment as to the moral worth or unworth of actions is possible by means of that idea only, which forms, therefore, the necessary foundation for every approach to moral perfection, however far the impediments inherent in human nature, the extent of which it is difficult to determine, may keep us removed from it.

The Platonic Republic has been supposed to [p. 316] be a striking example of purely imaginary perfection. It has become a byword, as something that could exist in the brain of an idle thinker only, and Brucker thinks it ridiculous that Plato could have said that no prince could ever govern well, unless he participated in the ideas. We should do better, however, to follow up this thought and endeavour (where that excellent philosopher leaves us without his guidance) to place it in a clearer light by our own efforts, rather than to throw it aside as useless, under the miserable and very dangerous pretext of its impracticability. A constitution founded on the greatest possible human freedom, according to laws which enable the freedom of each individual to exist by the side of the freedom of others (without any regard to the highest possible human happiness, because that must necessarily follow by itself), is, to say the least, a necessary idea, on which not only the first plan of a constitution or a state, but all laws must be based, it being by no means necessary to take account from the beginning of existing impediments, which may owe their origin not so much to human nature itself as to the actual neglect of true ideas in legislation. For nothing can be more mischievous and more unworthy a philosopher than the vulgar appeal to what is called adverse experience, which possibly might never have existed, if at the proper time institutions had been framed according to those ideas, and not according to crude [p. 317] concepts, which, because they were derived from experience only, have marred all good intentions. The more legislation and government are in harmony with that idea, the rarer, no doubt, punishments would become; and it is therefore quite rational to say (as Plato did), that in a perfect state no punishments would be necessary. And though this can never be realised, yet the idea is quite correct which sets up this maximum as an archetype, in order thus to bring our legislative constitutions nearer and nearer to the greatest possible perfection. Which may be the highest degree where human nature must stop, and how wide the chasm may be between the idea and its realisation, no one can or ought to determine, because it is this very freedom that may be able to transcend any limits hitherto assigned to it.

It is not only, however, where human reason asserts its free causality and ideas become operative agents (with regard to actions and their objects), that is to say, in the sphere of ethics, but also in nature itself, that Plato rightly discovered clear proofs of its origin from ideas. A plant, an animal, the regular plan of the cosmos (most likely therefore the whole order of nature), show clearly that they are possible according to ideas only; [p. 318] and that though no single creature, under the singular conditions of its existence, can fully correspond with the idea of what is most perfect of its kind (as little as any individual man with the idea of humanity, which, for all that, he carries in his mind as the archetype of all his actions), those ideas are nevertheless determined throughout in the highest understanding each by itself as unchangeable, and are in fact the original causes of things, although it can only be said of the whole of them, connected together in the universe, that it is perfectly adequate to the idea. If we make allowance for the exaggerated expression, the effort of the philosopher to ascend from the mere observing and copying of the physical side of nature to an architectonic system of it, teleologically, that is according to ideas, deserves respect and imitation, while with regard to the principles of morality, legislation, and religion, where it is the ideas themselves that make experience of the good possible, though they can never be fully realised in experience, such efforts are of very eminent merit, which those only fail to recognise who attempt to judge it according to empirical rules, the very validity of which, as principles, was meant to be denied by Plato. With regard to nature, it is experience no doubt which supplies us with rules, and is the foundation of all truth: with regard to moral laws, on the contrary, experience is, alas! but the source of illusion; and it is altogether reprehensible to derive or limit the laws of what we [p. 319] ought to do according to our experience of what has been done.

Instead of considering these subjects, the full development of which constitutes in reality the peculiar character and dignity of philosophy, we have to occupy ourselves at present with a task less brilliant, though not less useful, of building and strengthening the foundation of that majestic edifice of morality, which at present is undermined by all sorts of mole-tracks, the work of our reason, which thus vainly, but always with the same confidence, is searching for buried treasures. It is our duty at present to acquire an accurate knowledge of the transcendental use of the pure reason, its principles and ideas, in order to be able to determine and estimate correctly their influence and value. But before I leave this preliminary introduction, I beg those who really care for philosophy (which means more than is commonly supposed), if they are convinced by what I have said and shall still have to say, to take the term idea, in its original meaning, under their special protection, so that it should no longer be lost among other expressions, by which all sorts of representations are loosely designated, to the great detriment of philosophy. There is no lack of names adequate to express every kind of representation, without our having to encroach on the property of others. I shall [p. 320] give a graduated list of them. The whole class may be called representation (repraesentatio). Under it stands conscious representation, perception (perceptio). A perception referring to the subject only, as a modification of his state, is sensation (sensatio), while an objective sensation is called knowledge, cognition (cognitio). Cognition is either intuition or concept (intuitus vel conceptus). The former refers immediately to an object and is singular, the latter refers to it mediately, that is, by means of a characteristic mark that can be shared by several things in common. A concept is either empirical or pure, and the pure concept, so far as it has its origin in the understanding only (not in the pure image of sensibility) is called notion (notio). A concept formed of notions and transcending all possible experience is an idea, or a concept of reason. To any one who has once accustomed himself to these distinctions, it must be extremely irksome to hear the representation of red colour called an idea, though it could not even be rightly called a notion (a concept of the understanding).

[1 ]It is true, however, that he extended his concept of ideas to speculative knowledge also, if only it was pure, and given entirely a priori. He extended it even to mathematics, although they can have their object nowhere but in possible experience. In this I cannot follow him, nor in the mystical deduction of his ideas, and in the exaggerations which led him, as it were, to hypostasise them, although the high-flown language which he used, when treating of this subject, may well admit of a milder interpretation, and one more in accordance with the nature of things.