Critique of Pure Reason

Background

Early rationalism

Before Kant, it was generally held that truths of reason must be analytic, meaning that what is stated in the predicate must already be present in the subject (e.g., "An intelligent man is intelligent" or "An intelligent man is a man"). In either case, the judgment is analytic because it is ascertained by analyzing the subject. It was thought that all truths of reason, or necessary truths, are of this kind: that in all of them there is a predicate that is only part of the subject of which it is asserted. If this were so, attempting to deny anything that could be known a priori (e.g., "An intelligent man is not intelligent" or "An intelligent man is not a man") would involve a contradiction. It was therefore thought that the law of contradiction is sufficient to establish all a priori knowledge.

David Hume at first accepted the general view of rationalism about a priori knowledge. However, upon closer examination of the subject, Hume discovered that some judgments thought to be analytic, especially those related to cause and effect, were actually synthetic (i.e., no analysis of the subject will reveal the predicate). They thus depend exclusively upon experience and are therefore a posteriori.

Kant's rejection of Hume's empiricism

Before Hume, rationalists had held that effect could be deduced from cause; Hume argued that it could not and from this inferred that nothing at all could be known a priori in relation to cause and effect. Kant, who was brought up under the auspices of rationalism, was deeply impressed by Hume's skepticism. "I freely admit that it was the remembrance of David Hume which, many years ago, first interrupted my dogmatic slumber and gave my investigations in the field of speculative philosophy a completely different direction."

Kant decided to find an answer and spent at least twelve years thinking about the subject. Although the Critique of Pure Reason was set down in written form in just four to five months, while Kant was also lecturing and teaching, the work is a summation of the development of Kant's philosophy throughout those twelve years.

Kant's work was stimulated by his decision to take seriously Hume's skeptical conclusions about such basic principles as cause and effect, which had implications for Kant's grounding in rationalism. In Kant's view, Hume's skepticism rested on the premise that all ideas are presentations of sensory experience. The problem that Hume identified was that basic principles such as causality cannot be derived from sense experience only: experience shows only that one event regularly succeeds another, not that it is caused by it.

In section VI ("The General Problem of Pure Reason") of the introduction to the Critique of Pure Reason, Kant explains that Hume stopped short of considering that a synthetic judgment could be made 'a priori'. Kant's goal was to find some way to derive cause and effect without relying on empirical knowledge. Kant rejects analytical methods for this, arguing that analytic reasoning cannot tell us anything that is not already self-evident, so his goal was to find a way to demonstrate how the synthetic a priori is possible.

To accomplish this goal, Kant argued that it would be necessary to use synthetic reasoning. However, this posed a new problem: how is it possible to have synthetic knowledge that is not based on empirical observation; that is, how are synthetic a priori truths possible? This question is exceedingly important, Kant maintains, because he contends that all important metaphysical knowledge is of synthetic a priori propositions. If it is impossible to determine which synthetic a priori propositions are true, he argues, then metaphysics as a discipline is impossible.

Synthetic a priori judgments

Kant argues that there are synthetic judgments such as the connection of cause and effect (e.g., "... Every effect has a cause.") where no analysis of the subject will produce the predicate. Kant reasons that statements such as those found in geometry and Newtonian physics are synthetic judgments. Kant uses the classical example of 7 + 5 = 12. No amount of analysis will find 12 in either 7 or 5 and vice versa, since an infinite number of two numbers exist that will give the sum 12. Thus Kant concludes that all pure mathematics is synthetic though a priori; the number 7 is seven and the number 5 is five and the number 12 is twelve and the same principle applies to other numerals; in other words, they are universal and necessary. For Kant then, mathematics is synthetic judgment a priori. Conventional reasoning would have regarded such an equation to be analytic a priori by considering both 7 and 5 to be part of one subject being analyzed, however Kant looked upon 7 and 5 as two separate values, with the value of five being applied to that of 7 and synthetically arriving at the logical conclusion that they equal 12. This conclusion led Kant into a new problem as he wanted to establish how this could be possible: How is pure mathematics possible? This also led him to inquire whether it could be possible to ground synthetic a priori knowledge for a study of metaphysics, because most of the principles of metaphysics from Plato through to Kant's immediate predecessors made assertions about the world or about God or about the soul that were not self-evident but which could not be derived from empirical observation (B18-24). For Kant, all post-Cartesian metaphysics is mistaken from its very beginning: the empiricists are mistaken because they assert that it is not possible to go beyond experience and the dogmatists are mistaken because they assert that it is possible to go beyond experience through theoretical reason.

Therefore, Kant proposes a new basis for a science of metaphysics, posing the question: how is a science of metaphysics possible, if at all? According to Kant, only practical reason, the faculty of moral consciousness, the moral law of which everyone is immediately aware, makes it possible to know things as they are. This led to his most influential contribution to metaphysics: the abandonment of the quest to try to know the world as it is "in itself" independent of sense experience. He demonstrated this with a thought experiment, showing that it is not possible to meaningfully conceive of an object that exists outside of time and has no spatial components and is not structured following the categories of the understanding (Verstand), such as substance and causality. Although such an object cannot be conceived, Kant argues, there is no way of showing that such an object does not exist. Therefore, Kant says, the science of metaphysics must not attempt to reach beyond the limits of possible experience but must discuss only those limits, thus furthering the understanding of ourselves as thinking beings. The human mind is incapable of going beyond experience so as to obtain a knowledge of ultimate reality, because no direct advance can be made from pure ideas to objective existence.

Transcendental idealism

Kant's transcendental idealism should be distinguished from idealistic systems such as that of George Berkeley which deny all claims of extramental existence and consequently turn phenomenal objects into things-in-themselves. While Kant claimed that phenomena depend upon the conditions of sensibility, space and time, and on the synthesizing activity of the mind manifested in the rule-based structuring of perceptions into a world of objects, this thesis is not equivalent to mind-dependence in the sense of Berkeley's idealism. Kant defines transcendental idealism:

I understand by the transcendental idealism of all appearances the doctrine that they are all together to be regarded as mere representations and not things in themselves, and accordingly that time and space are only sensible forms of our intuition, but not determinations given for themselves or conditions of objects as things in themselves. To this idealism is opposed transcendental realism, which regards space and time as something given in themselves (independent of our sensibility).

Kant's approach

In Kant's view, a priori intuitions and concepts provide some a priori knowledge, which also provides the framework for a posteriori knowledge. Kant also believed that causality is a conceptual organizing principle imposed upon nature, albeit nature understood as the sum of appearances that can be synthesized according to a priori concepts.

In other words, space and time are a form of perceiving and causality is a form of knowing. Both space and time and conceptual principles and processes pre-structure experience.

Things as they are "in themselves"—the thing in itself, or das Ding an sich—are unknowable. For something to become an object of knowledge, it must be experienced, and experience is structured by the mind—both space and time being the forms of intuition (Anschauung; for Kant, intuition is the process of sensing or the act of having a sensation) or perception, and the unifying, structuring activity of concepts. These aspects of mind turn things-in-themselves into the world of experience. There is never passive observation or knowledge.

According to Kant, the transcendental ego—the "Transcendental Unity of Apperception"—is similarly unknowable. Kant contrasts the transcendental ego to the empirical ego, the active individual self subject to immediate introspection. One is aware that there is an "I," a subject or self that accompanies one's experience and consciousness. Since one experiences it as it manifests itself in time, which Kant proposes is a subjective form of perception, one can know it only indirectly: as object, rather than subject. It is the empirical ego that distinguishes one person from another providing each with a definite character.

Contents

The Critique of Pure Reason is arranged around several basic distinctions. After the two Prefaces (the A edition Preface of 1781 and the B edition Preface of 1787) and the Introduction, the book is divided into the Doctrine of Elements and the Doctrine of Method.

Doctrine of Elements and of Method

The Doctrine of Elements sets out the a priori products of the mind, and the correct and incorrect use of these presentations. Kant further divides the Doctrine of Elements into the Transcendental Aesthetic and the Transcendental Logic, reflecting his basic distinction between sensibility and the understanding. In the "Transcendental Aesthetic" he argues that space and time are pure forms of intuition inherent in our faculty of sense. The "Transcendental Logic" is separated into the Transcendental Analytic and the Transcendental Dialectic:

The Transcendental Analytic sets forth the appropriate uses of a priori concepts, called the categories, and other principles of the understanding, as conditions of the possibility of a science of metaphysics. The section titled the "Metaphysical Deduction" considers the origin of the categories. In the "Transcendental Deduction", Kant then shows the application of the categories to experience. Next, the "Analytic of Principles" sets out arguments for the relation of the categories to metaphysical principles. This section begins with the "Schematism", which describes how the imagination can apply pure concepts to the object given in sense perception. Next are arguments relating the a priori principles with the schematized categories.

The Transcendental Dialectic describes the transcendental illusion behind the misuse of these principles in attempts to apply them to realms beyond sense experience. Kant's most significant arguments are the "Paralogisms of Pure Reason", the "Antinomy of Pure Reason", and the "Ideal of Pure Reason", aimed against, respectively, traditional theories of the soul, the universe as a whole, and the existence of God. In the Appendix to the "Critique of Speculative Theology" Kant describes the role of the transcendental ideas of reason.

The Doctrine of Method contains four sections. The first section, "Discipline of Pure Reason", compares mathematical and logical methods of proof, and the second section, "Canon of Pure Reason", distinguishes theoretical from practical reason.

The divisions of the Critique of Pure Reason

Dedication

1. First and second Prefaces

2. Introduction

3. Transcendental Doctrine of Elements

A. Transcendental Aesthetic

(1) On space

(2) On time

B. Transcendental Logic

(1) Transcendental Analytic

a. Analytic of Concepts

i. Metaphysical Deduction

ii. Transcendental Deduction

b. Analytic of Principles

i. Schematism (bridging chapter)

ii. System of Principles of Pure Understanding

a. Axioms of Intuition

b. Anticipations of Perception

c. Analogies of Experience

d. Postulates of Empirical Thought (Refutation of Idealism)

iii. Ground of Distinction of Objects into Phenomena and Noumena

iv. Appendix on the Amphiboly of the Concepts of Reflection

(2) Transcendental Dialectic: Transcendental Illusion

I. Transcendental Doctrine of Elements

Transcendental Aesthetic

The Transcendental Aesthetic, as the Critique notes, deals with "all principles of a priori sensibility." As a further delimitation, it "constitutes the first part of the transcendental doctrine of elements, in contrast to that which contains the principles of pure thinking, and is named transcendental logic". In it, what is aimed at is "pure intuition and the mere form of appearances, which is the only thing that sensibility can make available a priori." It is thus an analytic of the a priori constitution of sensibility; through which "Objects are therefore given to us..., and it alone affords us intuitions." This in itself is an explication of the "pure form of sensible intuitions in general [that] is to be encountered in the mind a priori." Thus, pure form or intuition is the a priori "wherein all of the manifold of appearances is intuited in certain relations." from this, "a science of all principles of a priori sensibility [is called] the transcendental aesthetic." The above stems from the fact that "there are two stems of human cognition...namely sensibility and understanding."

This division, as the critique notes, comes "closer to the language and the sense of the ancients, among whom the division of cognition into αισθητα και νοητα is very well known." An exposition on a priori intuitions is an analysis of the intentional constitution of sensibility. Since this lies a priori in the mind prior to actual object relation; "The transcendental doctrine of the senses will have to belong to the first part of the science of elements, since the conditions under which alone the objects of human cognition are given precede those under which those objects are thought".

Kant distinguishes between the matter and the form of appearances. The matter is "that in the appearance that corresponds to sensation" (A20/B34). The form is "that which so determines the manifold of appearance that it allows of being ordered in certain relations" (A20/B34). Kant's revolutionary claim is that the form of appearances—which he later identifies as space and time—is a contribution made by the faculty of sensation to cognition, rather than something that exists independently of the mind. This is the thrust of Kant's doctrine of the transcendental ideality of space and time.

Kant's arguments for this conclusion are widely debated among Kant scholars. Some see the argument as based on Kant's conclusions that our representation (Vorstellung) of space and time is an a priori intuition. From here Kant is thought to argue that our representation of space and time as a priori intuitions entails that space and time are transcendentally ideal. It is undeniable from Kant's point of view that in Transcendental Philosophy, the difference of things as they appear and things as they are is a major philosophical discovery. Others see the argument as based upon the question of whether synthetic a priori judgments are possible. Kant is taken to argue that the only way synthetic a priori judgments, such as those made in geometry, are possible is if space is transcendentally ideal.

Transcendental Logic

In the Transcendental Logic, there is a section (titled The Refutation of Idealism) that is intended to free Kant's doctrine from any vestiges of subjective idealism, which would either doubt or deny the existence of external objects (B274-79). Kant's distinction between the appearance and the thing-in-itself is not intended to imply that nothing knowable exists apart from consciousness, as with subjective idealism. Rather, it declares that knowledge is limited to phenomena as objects of a sensible intuition. In the Fourth Paralogism ("... A Paralogism is a logical fallacy"), Kant further certifies his philosophy as separate from that of subjective idealism by defining his position as a transcendental idealism in accord with empirical realism (A366–80), a form of direct realism. "The Paralogisms of Pure Reason" is the only chapter of the Dialectic that Kant rewrote for the second edition of the Critique of Pure Reason. In the first edition, the Fourth Paralogism offers a defence of transcendental idealism, which Kant reconsidered and relocated in the second edition.

Whereas the Transcendental Aesthetic was concerned with the role of the sensibility, the Transcendental Logic is concerned with the role of the understanding, which Kant defines as the faculty of the mind that deals with concepts. Knowledge, Kant argued, contains two components: intuitions, through which an object is given to us in sensibility, and concepts, through which an object is thought in understanding. In the Transcendental Aesthetic, he attempted to show that the a priori forms of intuition were space and time, and that these forms were the conditions of all possible intuition. It should therefore be expected that we should find similar a priori concepts in the understanding, and that these pure concepts should be the conditions of all possible thought. The Logic is divided into two parts: the Transcendental Analytic and the Transcendental Dialectic. The Analytic Kant calls a "logic of truth"; in it he aims to discover these pure concepts which are the conditions of all thought, and are thus what makes knowledge possible. The Transcendental Dialectic Kant calls a "logic of illusion"; in it he aims to expose the illusions that we create when we attempt to apply reason beyond the limits of experience.

The idea of a transcendental logic is that of a logic that gives an account of the origins of our knowledge as well as its relationship to objects. Kant contrasts this with the idea of a general logic, which abstracts from the conditions under which our knowledge is acquired, and from any relation that knowledge has to objects. According to Helge Svare, "It is important to keep in mind what Kant says here about logic in general, and transcendental logic in particular, being the product of abstraction, so that we are not misled when a few pages later he emphasizes the pure, non-empirical character of the transcendental concepts or the categories."

II. Transcendental Doctrine of Method

The second book in the Critique, and by far the shorter of the two, attempts to lay out the formal conditions of the complete system of pure reason.

In the Transcendental Dialectic, Kant showed how pure reason is improperly used when it is not related to experience. In the Method of Transcendentalism, he explained the proper use of pure reason.

The discipline of pure reason

In section I, the discipline of pure reason in the sphere of dogmatism, of chapter I, the discipline of pure reason, of Part II, transcendental discipline of method, of the Critique of Pure Reason, Kant enters into the most extensive discussion of the relationship between mathematical theory and philosophy.

Discipline is the restraint, through caution and self-examination, that prevents philosophical pure reason from applying itself beyond the limits of possible sensual experience. Philosophy cannot possess dogmatic certainty. Philosophy, unlike mathematics, cannot have definitions, axioms or demonstrations. All philosophical concepts must be ultimately based on a posteriori, experienced intuition. This is different from algebra and geometry, which use concepts that are derived from a priori intuitions, such as symbolic equations and spatial figures. Kant's basic intention in this section of the text is to describe why reason should not go beyond its already well-established limits. In section I, the discipline of pure reason in the sphere of dogmatism, Kant clearly explains why philosophy cannot do what mathematics can do in spite of their similarities. Kant also explains that when reason goes beyond its own limits, it becomes dogmatic. For Kant, the limits of reason lie in the field of experience as, after all, all knowledge depends on experience. According to Kant, a dogmatic statement would be a statement that reason accepts as true even though it goes beyond the bounds of experience.

Restraint should be exercised in the polemical use of pure reason. Kant defined this polemical use as the defense against dogmatic negations. For example, if it is dogmatically affirmed that God exists or that the soul is immortal, a dogmatic negation could be made that God does not exist or that the soul is not immortal. Such dogmatic assertions cannot be proved. The statements are not based on possible experience. In section II, the discipline of pure reason in polemics, Kant argues strongly against the polemical use of pure reason. The dogmatic use of reason would be the acceptance as true of a statement that goes beyond the bounds of reason while the polemic use of reason would be the defense of such statement against any attack that could be raised against it. For Kant, then, there cannot possibly be any polemic use of pure reason. Kant argues against the polemic use of pure reason and considers it improper on the grounds that opponents cannot engage in a rational dispute based on a question that goes beyond the bounds of experience.

The canon of pure reason

The canon of pure reason is a discipline for the limitation of pure reason. The analytic part of logic in general is a canon for the understanding and reason in general. However, the Transcendental Analytic is a canon of the pure understanding for only the pure understanding is able to judge synthetically a priori.

The speculative propositions of God, immortal soul, and free will have no cognitive use but are valuable to our moral interest. In pure philosophy, reason is morally (practically) concerned with what ought to be done if the will is free, if there is a God, and if there is a future world. Yet, in its actual practical employment and use, reason is only concerned with the existence of God and a future life. Basically, the canon of pure reason deals with two questions: Is there a God? Is there a future life? These questions are translated by the canon of pure reason into two criteria: What ought I to do? and What may I hope for? yielding the postulates of God's own existence and a future life, or life in the future.

The greatest advantage of the philosophy of pure reason is negative, the prevention of error. Yet moral reason can provide positive knowledge. There cannot be a canon, or system of a priori principles, for the correct use of speculative reason. However, there can be a canon for the practical (moral) use of reason.

Reason has three main questions and answers:

What can I know? We cannot know, through reason, anything that cannot be a possible sense experience; ("that all our knowledge begins with experience there can be no doubt")

What should I do? Do that which will make you deserve happiness;

What may I hope? We can hope to be happy as far as we have made ourselves deserving of it through our conduct.

Reason tells us that there is a God, the supreme good, who arranges a future life in a moral world. If not, moral laws would be idle fantasies. Our happiness in that intelligible world will exactly depend on how we have made ourselves worthy of being happy. The union of speculative and practical reason occurs when we see God's reason and purpose in nature's unity of design or general system of ends. The speculative extension of reason is severely limited in the transcendental dialectics of the Critique of Pure Reason, which Kant would later fully explore in the Critique of Practical Reason.

The architectonic of pure reason

All knowledge from pure reason is architectonic in that it is a systematic unity. The entire system of metaphysic consists of: (1.) Ontology—objects in general; (2.) Rational Physiology—given objects; (3.) Rational cosmology—the whole world; (4.) Rational Theology—God. Metaphysic supports religion and curbs the extravagant use of reason beyond possible experience. The components of metaphysic are criticism, metaphysic of nature, and metaphysic of morals. These constitute philosophy in the genuine sense of the word. It uses science to gain wisdom. Metaphysic investigates reason, which is the foundation of science. Its censorship of reason promotes order and harmony in science and maintains metaphysic's main purpose, which is general happiness. In chapter III, the architectonic of pure reason, Kant defines metaphysics as the critique of pure reason in relation to pure a priori knowledge. Morals, analytics and dialectics for Kant constitute metaphysics, which is philosophy and the highest achievement of human reason.

The history of pure reason

Kant writes that metaphysics began with the study of the belief in God and the nature of a future world, beyond this immediate world as we know it, in our common sense. It was concluded early that good conduct would result in happiness in another world as arranged by God. The object of rational knowledge was investigated by sensualists (Epicurus), and intellectualists (Plato). Sensualists claimed that only the objects of the senses are real. Intellectualists asserted that true objects are known only by the understanding mind. Aristotle and Locke thought that the pure concepts of reason are derived only from experience. Plato and Leibniz contended that they come from reason, not sense experience, which is illusory. Epicurus never speculated beyond the limits of experience. Locke, however, said that the existence of God and the immortality of the soul could be proven. Those who follow the naturalistic method of studying the problems of pure reason use their common, sound, or healthy reason, not scientific speculation. Others, who use the scientific method, are either dogmatists (Wolff) or skeptics (Hume). In Kant's view, all of the above methods are faulty. The method of criticism remains as the path toward the completely satisfying answers to the metaphysical questions about God and the future life in another world.

Terms and phrases

a priori versus a posteriori

Analytic versus synthetic

Appearance

Category

concept versus object of sense perception

Empirical versus pure

intuition

Manifold of the appearances

Object

Phenomena versus noumena

Schema

Transcendental idealism

variant translations of Vorstellung: presentation or representation

Intuition and concept

Kant distinguishes between two different fundamental types of representation: intuitions and concepts:

Concepts are "mediate representations" (see A68/B93). Mediate representations represent things by representing general characteristics of things. For example, consider a particular chair. The concepts "brown," "wooden," "chair," and so forth are, according to Kant, mediate representations of the chair. They can represent the chair by representing general characteristics of the chair: being brown, being wooden, being a chair, and so forth.

Intuitions are "immediate representations" (see B41), that is, representations that represent things directly. One's perception of the chair is, according to Kant, an immediate representation. The perception represents the chair directly, and not by means of any general characteristics.

Kant divides intuitions in the following ways:

Kant distinguishes intuitions into pure intuitions and empirical intuitions. Empirical intuitions are intuitions that contain sensation. Pure intuitions are intuitions that do not contain any sensation (A50/B74). An example of an empirical intuition would be one's perception of a chair or another physical object. All such intuitions are immediate representations that have sensation as part of the content of the representation. The pure intuitions are, according to Kant, those of space and time, which are our mind's subjective condition of coordinating sensibilia. Our representations of space and time are not objective and real, but immediate representations that do not include sensation within those representations. Thus both are pure intuitions.

Kant also divides intuitions into two groups in another way. Some intuitions require the presence of their object, i.e. of the thing represented by the intuition. Other intuitions do not. (The best source for these distinctions is Kant's Lectures on Metaphysics.) We might think of these in non-Kantian terms as first, perceptions, and second, imaginations (see B151). An example of the former: one's perception of a chair. An example of the latter: one's memory (Gedachtnis/Erinnerung) of a chair that has subsequently been destroyed. Throughout the Transcendental Aesthetic, Kant seems to restrict his discussion to intuitions of the former type: intuitions that require the presence of their object.

Tables of principles and categories of understanding in the critique

Kant borrowed the term categories from Aristotle, but with the concession that Aristotle's own categorizations were faulty. Aristotle's imperfection is apparent from his inclusion of "some modes of pure sensibility (quando, ubi, situs, also prius, simul), also an empirical concept (motus), none of which can belong to this genealogical register of the understanding."

Kant's divisions, however, are guided by his search in the mind for what makes synthetic a priori judgments possible.

Reception

Early responses: 1781–1793

The Critique of Pure Reason was the first of Kant's works to become famous. According to the philosopher Frederick C. Beiser, it helped to discredit rationalist metaphysics of the kind associated with Leibniz and Wolff which had appeared to provide a priori knowledge of the existence of God, although Beiser notes that this school of thought was already in decline by the time the Critique of Pure Reason was published. In his view, Kant's philosophy became successful in the early 1790s partly because Kant's doctrine of "practical faith" seemed to provide a justification for moral, religious, and political beliefs without an a priori knowledge of God. However, the Critique of Pure Reason received little attention when it was first published. Kant did not expect reviews from anyone qualified to appraise the work, and initially heard only complaints about its obscurity. The theologian and philosopher Johann Friedrich Schultz wrote that the public saw the work as "a sealed book" consisting in nothing but "hieroglyphics". The first review appeared in the Zugaben zu den Göttinger gelehrte Anzeigen in 1782. The review, which denied that there is any distinction between Kant's idealism and that of Berkeley, was anonymous and became notorious. Kant reformulated his views because of it, redefining his transcendental idealism in the Prolegomena to Any Future Metaphysics (1783) and the second edition of the Critique of Pure Reason. The review was denounced by Kant, but defended by Kant's empiricist critics, and the resulting controversy drew attention to the Critique of Pure Reason.

Kant believed that the anonymous review was biased and deliberately misunderstood his views. He discussed it in an appendix of the Prolegomena, accusing its author of failing to understand or even address the main issue addressed in the Critique of Pure Reason, the possibility of synthetic a priori judgments, and insisting on the distinction between transcendental idealism and the idealism of Berkeley. In a letter to Kant, the philosopher Christian Garve admitted to having written the review, which he disowned due to editorial changes outside his control. Though Garve did not inform Kant of this, the changes had been made by Johann Georg Heinrich Feder. Following the controversy over Garve's review, there were no more reviews of the Critique of Pure Reason in 1782 except for a brief notice. The work received greater attention only in 1784, when Shultz's commentary was published and a review by the philosopher and historian of philosophy Dietrich Tiedemann was published in the Hessische Beyträge zur Gelehrsamkeit und Kunst. Tiedemann attacked the possibility of the synthetic a priori and defended the possibility of metaphysics. He denied the synthetic status of mathematical judgments, maintaining that they can be shown to be analytic if the subject term is analyzed in full detail, and criticized Kant's theory of the a priori nature of space, asking how it was possible to distinguish one place from another when the parts of absolute space are identical in themselves. Kant issued a hostile reaction. He maintained that Tiedemann did not understand the problems facing the critical philosophy.

Later responses

The Critique of Pure Reason has exerted an enduring influence on Western philosophy. The constructive aspect of the work, Kant's attempt to ground the conditions for the possibility of objects in the conditions of experience, helped bring about the development of German idealism. The work also influenced Young Hegelians such as Bruno Bauer, Ludwig Feuerbach and Karl Marx, and also, Friedrich Nietzsche, whose philosophy has been seen as a form of "radical Kantianism" by Howard Caygill. Other interpretations of the Critique by philosophers and historians of philosophy have stressed different aspects of the work. The late 19th-century neo-Kantians Hermann Cohen and Heinrich Rickert focused on its philosophical justification of science, Martin Heidegger and Heinz Heimsoeth on aspects of ontology, and Peter Strawson on the limits of reason within the boundaries of sensory experience. Hannah Arendt and Jean-François Lyotard dealt with its work of orientation of a limited understanding in the field of world history. According to Physiologist Homer W. Smith,

Kant's Critique of Pure Reason is important because it threw the philosophy of the nineteenth century into a state of temporary confusion. That it failed to prove its cardinal point, the existence of a priori truths, rapidly became clear. If there were no promises the fulfillment of which was to be expected, 'lying' would indeed be a universal law of action, and by Kant's own criterion lying would now be moral, and it would be truth that would be immoral.

Legacy

Many titles have been used by different authors in reference or as a tribute to Kant's main Critique, or his other, less famous books using the same basic concept, Critique of Practical Reason and Critique of Judgment. Since the 18th century, books using "critique" in their title became common. Also, when "reason" is added after an adjective which qualifies this reason, this is usually a reference to Kant's most famous book. A few examples:

"Critique of the Kantian Philosophy" (1818), as an appendix of The World as Will and Representation by Arthur Schopenhauer;

Critique of Dialectical Reason (1960), by Jean-Paul Sartre;

Critique of Cynical Reason (1983), by Peter Sloterdijk;

Critique of Postcolonial Reason (1999), by Gayatri Chakravorty Spivak;

Critique of Black Reason (2017 translation, 2013 original), by Achille Mbembe;

Critique of Impure Reason (2021), by Steven James Bartlett

English translations

Critick of Pure Reason: Translated from the Original of Immanuel Kant. Translated by Francis Haywood. London: William Pickering. 1838. OCLC 457804778. First English translation.

Critique of Pure Reason. Translated by John Meiklejohn. 1855 – via Project Gutenberg.

Critique of Pure Reason. Translated by Thomas Kingsmill Abbott. 1873.

Critique of Pure Reason. Translated by Friedrich Max Müller. The Macmillan Company. 1881. (Introduction by Ludwig Noiré)

Critique of Pure Reason. Translated by Norman Kemp Smith. Palgrave Macmillan. 1929. ISBN 1-4039-1194-0. Archived from the original on 2009-04-27. {{cite book}}: ISBN / Date incompatibility (help)

Critique of Pure Reason. Translated by Wolfgang Schwartz. Scientia Verlag und Antiquariat. 1982. ISBN 978-3-5110-9260-3.

Critique of Pure Reason. Translated by Werner S. Pluhar, including the 24-pp. Introduction by Patricia W. Kitcher. Hackett Publishing. 1996. ISBN 978-0-87220-257-3.

Critique of Pure Reason, Abridged. Translated by Werner S. Pluhar. Hackett Publishing. 1999. ISBN 978-1-6246-6605-6.

Critique of Pure Reason. Translated and edited by Paul Guyer and Allen W. Wood. Cambridge University Press. 1999. ISBN 978-0-5216-5729-7.{{cite book}}: CS1 maint: others (link)

Critique of Pure Reason. Translated by Marcus Weigelt. Penguin Books. 2007. ISBN 978-0-1404-4747-7.