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The greatest modern philosopher?

Portrait of Immanuel Kant

Still living in the tradition of the Philosophy of Consciousness since Descartes, Immanuel Kant was quite unique in that he attempted to synthesize the Continental Rationalism of Descartes-Spinoza-Leibniz and the British Empiricism of Locke-Berkeley-Hume into one so called Critical Philosophy of his own by being inspired by both, eliminating the faults of both thoughts and critically unifying the strengths of these opposing philosophical thoughts.

Despite the claim that Kant renovated the philosophy by opening up the third way in the synthesis of the Continental Rationalism and the British Empiricism, Kant remained in the approach of or within Consciousness and by means of Self-reflection or Introspection. In other words, the approach Kant always took was, whether it was the dogmatic-pre-critical period or the critical period alike, the Approach of Consciousness which overwhelms the history of contemporary philosophy since Descartes even to the philosophers of modernity such as Husserl and Heidegger.

Below are some articles I found most useful in my study of Kant:

A.Kant: from Wikipedia
B.Immanuel Kant (1724-1804) by Matt McCormick
C.Königsberg Confidential: Book Review
D.Immanuel Kant (1724-1804) by Kelley L. Ross, Ph.D

A. Kant: from Wikipedia

Immanuel Kant (April 22, 1724 – February 12, 1804) was a German philosopher from Prussia, generally regarded as one of Europe's most influential thinkers and the last major philosopher of the Enlightenment. He had a major impact on the Romantic and Idealist philosophies of the 19th century, and his work was the starting point for Hegel.

Kant is best known for his view — called transcendental idealism — that we bring innate forms and concepts to the raw experience of the world, which would otherwise be unknowable. We perceive the world by means of our senses and innate intuitions, he argued, and therefore the thing-in-itself cannot be known. Our objects of knowledge, filtered by our senses, are simply appearances.
His epistemology, or theory of knowledge, was an attempt to solve the conflict between the rationalists, who said that knowledge without experience is possible, and the empiricists, who argued that experience is all there is. Kant bridged the gap between these two positions with the opening statement of his Critique of Pure Reason: "But though all our knowledge begins with experience, it does not follow that it all arises out of experience."

2.The Critique of Pure Reason
3.Kant's moral philosophy
4.Further reading

1. Background
Kant was born, lived and died in Königsberg, the capital of Prussia (later known as East Prussia). His parents baptized him as Emanuel Kant, which Kant later , when he learned Hebrew, changed to Immanuel. He spent much of his youth as a solid, albeit unspectacular, student, and lived a very regulated life: the walk he took at three-thirty every afternoon was so punctual that local housewives would set their clocks by him. He remained unmarried and owned only one piece of art in his household, advocating the absence of passion in favor of logic. He never left Prussia and rarely stepped outside his own home town. However, despite his reputation for being a solitary man, he was considered a sociable person and would regularly have guests over for dinner, insisting that company and laughter were good for his constitution. He was a respected and competent university professor for most of his life, although he was in his late fifties before he did anything that would bring him historical repute.

He entered the local university in 1740, and studied the philosophy of Leibniz and Christian Wolff under Martin Knutsen, a follower of Wolff. He also studied the new mathematics of Sir Isaac Newton and, in 1746, wrote a paper on measurement, reflecting Leibniz's influence. In 1755, he became a private lecturer at the University, and while there published "Inquiry into the Distinctness of the Principles of Natural Theology and Morals", where he examined the problem of having a logical system of philosophy that connected with the world of natural philosophy, a concern typical of the period. In this paper, he proposed what later become known as the Kant-Laplace theory of planetary formation, wherein the planets formed from rotating protoplanetary disks of gas. Kant was also the first recorded scholar to postulate (as is true) that some of the faint nebulae one can see with a small telescope (or in one case, with the naked eye) were external galaxies or, as he called them, island universes. Kant's prescient remarks on island universes.

In 1763, he wrote The Only Possible Ground of Proof for a Demonstration of God's Existence, which questioned the ontological argument for God put forward by Saint Anselm of Canterbury in the 11th century, namely that the greatest of all possible ideas must include the attribute of existence, because if it does not, it is not the greatest of all possible ideas. Therefore, God, who by definition is the greatest of all possible ideas, must exist. Rene Descartes put forward a similar argument in the Fifth Meditation.

Kant was of the rather curious conviction that a person did not have a firm direction in life until their thirty-ninth year; when this came and passed and he was just a minor metaphysician in a Prussian university, a brief mid-life crisis ensued. In 1766, he was appointed Second Librarian of the Royal Library, a somewhat prestigous government position. In 1770, he became a full professor at Königsberg, and began reading the works of David Hume. Hume was fiercely empirical, scorned all metaphysics, and systematically debunked great quantities of it. His most famous thesis is that nothing in our experience can justify the assumption that there are "causal powers" inherent in things — that, for example, when one billiard ball strikes another, the second must move. Kant found Hume's argument irrefutable but his conclusions unacceptable. "I wilfully admit that it was David Hume that woke me from my dogmatic slumber", he would later write.

For the next 10 years, he worked on the architecture of his own philosophy, beginning with what he called "the scandal of reality", namely that there exists no proof of the existence of "external reality" or the outside world. In 1781, he released the Critique of Pure Reason, one of the most influential, widely cited, and widely disputed works in Western philosophy. He followed this with Groundwork of the Metaphysics of Morals, then in 1788, the Critique of Practical Reason and in 1790, the Critique of Judgement. The effect was immediate in the German-speaking world, with readership including Ludwig van Beethoven and Johann Wolfgang von Goethe. But the attention was far from universally approving: on the contrary, almost every aspect of his writing was attacked and criticized fiercely, particularly his ideas on categories, the place of free will and determinism, and whether we can have knowledge of external reality. His early critics included Johann Schaumann, Friedrich Heinrich Jacobi and Hermann Pistorius. Pistorius' criticisms were particularly influential and are still cited today.
Inscription on Kant's tombstone
The inscription near Kant's tomb.

The Critique of Practical Reason dealt with morality, or action, in the same way that the first Critique dealt with knowledge, and the Critique of Judgement dealt with the various uses of our mental powers that neither confer factual knowledge nor determine us to action, such as aesthetic judgment, for example of the beautiful and sublime, and teleological judgment, that is, construing things as having "purposes". As Kant understood them, aesthetic and teleological judgment connected our moral and empirical judgments to one another, unifying his system. Two shorter works, the Prolegomena to any Future Metaphysics and the Groundwork to the Metaphysics of Morals treated the same matter as the first and second critiques respectively, in a more cursory form — assuming the answer and working backward, so to speak. They serve as his introductions to the critical system.

The epistemological material of the first Critique was put into application in the Metaphysical Foundations of Natural Science; the ethical dictums of the second were put into practice in Metaphysics of Morals. His work on moral philosophy is best known for its formulation of a basic tenet of ethics, an extension of the Golden Rule, which Kant called the categorical imperative: "Act only on that maxim whereby thou canst at the same time will that it should become a universal law." This extends the rule so as not only to demand fairness one would expect returned, but also to will that others will treat each other similarly.

Kant also wrote a number of semi-popular essays on history, politics, and the application of philosophy to life. When he died in 1804, he was working on a projected fourth critique, having come to the conviction that his system was incomplete; this incomplete manuscript has been published as Opus Postumum.

His tomb and its pillared enclosure outside the cathedral in Königsberg is one of the few artifacts of German times preserved by the Soviets after they conquered East Prussia in 1945. A replica of a statue of Kant that stood in front of the university was donated by a German entity in 1991 and placed on the original pediment. The inscription near his tomb reads: Two things fill the mind with ever new and increasing admiration and awe, the more often and perseveringly my thinking engages itself with them: the starry heavens above me and the moral law within me.

2. The Critique of Pure Reason
Kant's most widely read and most influential book is Critique of Pure Reason (1781) - his attempt to work past what he saw as the unacceptable conclusions of David Hume. Kant wanted to find the limitations of Reason, and its application to such important philosophical questions as whether there is a God, the immortality of the soul, and freedom. A person who studies Kant's Critique of Pure Reason, should also study Hume's Enquiry Concerning Human Understanding in order to understand what caused Kant to become so interested in writing his three Critiques.

Hume's conclusions, Kant realized, rested on the premise that knowledge is empirical at its root. The problem that Hume identified was that basic principles like cause and effect cannot be empirically derived. Kant's goal, then, 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 can't tell you anything that isn't already self-evident. Instead, Kant argued that we would need to use synthetic reasoning. But this posed a new problem - how can one have synthetic knowledge that is not based on empirical observation - that is, how can we have synthetic a priori truths. Kant's famous quote from the first third of the book is, “thoughts without content [are] empty, and intuitions without concepts [are] blind.”

Kant lecturing Russian officers
Immanuel Kant, lecturing to Russian officers
 by I. Soyockina / V. Gracov, the Kant Museum

Kant did not have any trouble showing that we do have synthetic a priori truths. After all, he reasoned, geometry and Newtonian physics are synthetic a priori knowledges and are fundamentally true. The issue was showing how one could ground synthetic a priori knowledge for a study of metaphysics. This led to his most influential contribution to metaphysics - the abandonment of the quest to try to know the world in itself, instead acknowledging that there is no way to determine whether something is experienced the way it is because that's the way it is, or because the faculties we have with which to perceive and experience are constructed such that we experience it in a given way. He demonstrated this with a thought experiment, showing that we cannot meaningfully conceive of an object that exists outside of time and has no spatial components. Although we cannot conceive of such an object, Kant argues, there is no way of showing that such an object does not exist. Therefore, Kant says, metaphysics must not try to talk about what exists, but instead about what is perceived, and how it is perceived.

This insight allows Kant to set up a distinction between phenomena and noumena - phenomena being that which can be experienced, and noumena being things that are beyond the possibility of experience - things in themselves. Nothing can be truly experienced or else you would experience the noumena itself. The phenomena is only the representation of the object/noumena that a person recieves through their sensibilities. The phenomena is a representation of an object not the object itself, nothing more. Kant then discussed and expanded on the faculties of experience we have, and thus was able to come up with a system of metaphysics that applied to the world as we perceive it.
Kant termed his critical philosophy "transcendental idealism." While the exact interpretation of this phrase is contentious, one way to start to understand it is through Kant's comparison in the second preface to the "Critique of Pure Reason" of his critical philosophy to Copernicus' revolution in astronomy. Kant writes: "Hitherto it has been assumed that all our knowledge must conform to objects. But all attempts to extend our knowledge of objects by establishing something in regard to them a priori, by means of concepts, have, on this assumption, ended in failure. We must therefore make trial whether we may not have more success in the tasks of metaphysics, if we suppose that objects must conform to our knowledge" [Bxvi]. Just as Copernicus revolutionized astronomy by changing the point of view, Kant's critical philosophy asks what the a priori conditions for our knowledge of objects in the world might be. Transcendental idealism describes this method of seeking the conditions of the possibility of our knowledge of the world.

Kant's "transcendental idealism" should be distinguished from idealistic systems such as Berkeley's. While Kant claimed that phenomena depend upon the conditions of sensibility, space and time, this thesis is not equivalent to mind-dependence in the sense of Berkeley's idealism. For Berkeley, something is an object only if it can be perceived. For Kant, on the other hand, perception does not provide the criterion for the existence of objects. Rather, the conditions of sensibility - space and time - provide the "epistemic conditions", to borrow a phrase from Henry Allison, required for us to know objects in the phenomenal world.

Kant had wanted to discuss metaphysical systems but discovered "the scandal of philosophy" — you cannot decide what the proper terms for a metaphysical system are until you have defined the field, and you cannot define the field until you have defined the limit of the field of physics first. 'Physics' in this sense means, roughly, the discussion of the perceptible world.

Kant's Postulates in the Transcendental Analytic
In the Transcendental Analytic Kant presents the three postulates: the possible, actual, and necessity. Kant states that the postulate of the possibility of things requires that the concept of the things should agree with the formal conditions of an experience, with the conditions of intuition and concepts, in general (Kant, A220). What agrees with the formal conditions of experience is possible, and everything that does not agree with it is not possible; experience validates concepts. Kant states that an empty concept is that which contains a synthesis and as not related to any object, if this synthesis does not belong to experience either as derived from it, in which case it is an empirical concept, or as being on a prior condition upon which experience in general in its formal aspects rest, in which case it is a pure concept.

In order to be valid a concept, it is indeed a necessary logical condition that a concept of the possible must not contain any contradiction. This idea of a concept not having a contradiction is very important due to Kant's use it in developing a morality and ethics; an example will be given later in this essay as a demonstration. Even if a concept does not have a contradiction this by itself is not sufficient to make the concept valid nor by any means sufficient to determine objective reality of a concept. An example of a concept that contains no contradiction but is not valid is the concept of a figure enclosed within two straight lines, although it contains no contradiction it is not valid (Kant, A221). As Kant states the impossibility arises in the connection with its construction in space.

Having stated postulate #1, Kant then explains what happens if we do not stick to his definition of it. Kant explains that if we should seek to frame quite new concepts of substances, forces, reciprocal actions, from the material which perception presents to us, without experience itself yielding the example of their connection, we should be occupying ourselves with mere fancies, of whose possibility there is no criterion since we have neither borrowed these concepts directly from experience, nor have taken experience as our instructress in their formation (Kant, A222). An example of a concept commonly held by intellectuals during his time, and still held by contemporaries, would be those of psychic and remote viewing. Kant defines these two concepts as a substance which would be permanently present in space, but without filling it (like that mode of existence intermediate between matter and thinking being which some would seek to introduce), or a special ultimate mental power of intuitively anticipating the future (and not merely inferring it), or lastly a power of standing in community of thought with other men, however distant they may be-are concepts the possibility of which is altogether groundless, as they cannot be based on experience and its known laws as the example of Immanuel Sweden Borg (Kant, B270). Kant ends his discussion of the possibility postulate by stating that in order to think inconcreto, you must call experience to you aid.

After defining the postulate of the possible Kant then explains the postulate of actuality. Kant states that in order for a concept to be actual it does not demand immediate perception (and therefore, sensation of which we are conscious) of the object whose existence is to be known. Kant states that if a concept precedes perception this signifies the concept mere possibility, in order to be actual perception must supply the content to the concept for its sole mark of actuality. An example of a concept that has fulfilled the actuality postulate would be magnetism. Kant states that thus from the perception of the attracted iron filings we know of the existence of a magnetic matter pervading all bodies, although the constitution of our organs cuts us off from all immediate perception of this medium (Kant, A226). Another example of a concept that fulfills the actuality postulate would be gravity.

Kant rejects material idealism which states that the existence of objects in space outside of us either to be merely doubtful and indemonstrable (Descartes) or to be false and impossible (Berkley). Problematic Idealism, lead by Descartes, states that the only empirical assertion that is certain is “I am.” Kant states that in order to overcome problematic idealism a proof must show that we have experience, not merely an imagination of things. Dogmatic Idealism, lead by Bishop Berkley, states that things in space are imaginary entities, and Kant claims that he already refuted this claim in the Transcendental Aesthetic.

The thesis Kant uses to refute idealism states that the mere, but empirically determined, consciousness of my own existence proves the existence of objects in space outside me. (1.) In order to prove the existence of objects outside of him he states that he is conscious of his own existence a determined in time. (2.) All determinations of time presuppose something permanent in perception. (3) The permanent cannot be in me, since it is only through the permanent that my existence in time can itself be determined. Kant concludes by stating that, “Thus perception of this permanent is possible only through a thing outside me and not through the mere representation of a thing outside me; and consequently the determination of my existence in time is possible only through the existence of an actual thing which I perceive outside me.”

Kant states that the “game of idealism” has been turned against itself. Idealism, he states, assumes that only immediate experience is inner experience, and from it we can only infer outer thing only in an untrustworthy manner, so the cause of the representation, which we ascribe, perhaps falsely to outer things may be in ourselves. For Kant outer experience is immediate through time determination. Although it is immediate experience it does not immediately include any knowledge of subject no empirical knowledge. For Kant inner experience is itself possible only relating through out experience.

Kant's third postulate is the material necessity in existence. He states that objects of the senses cannot be known completely a priori, but only comparatively a priori. He states that concepts which in its connection with the actual is determined in accordance with the universal conditions of experience, is (that is, exist as) necessary. Kant argues that nothing happens through blind chance. He claims that no necessity in nature is blind, but always conditional and intelligibly necessary. Nature also forbids any leap on the senses of appearance, and forbids any gap of cleft between appearances.

3. Kant's moral philosophy
Kant develops his moral philosophy in three works: Fundamental Principles of the Metaphysic of Morals  (1785), Critique of Practical Reason (1788) and Metaphysics of Morals (1798). A devotee of Kant who studies his moral philosophy should also read his "Lectures on Ethics."
Under this heading Kant is probably best known for his theory about a single, general moral obligation that explains all other moral obligations we have: the Categorical Imperative. Here, as elsewhere in his critical philosophy, he believed that the moral law must be a principle of reason itself, and could not be based on contingent facts about the world (e.g., what would make us happy). Accordingly, he believed that morality applies to all and only rational beings. Kant's believed that moral law should not be called moral just because someone said it. The test of a future morality for Kant is not that a person said that it should be so, but because it is categorically imperative.

A categorical imperative, generally speaking, is an unconditional obligation, or an obligation that we have regardless of our will or desires (contrast with hypothetical imperative).

Our moral duties can be derived from the categorical imperative. The categorical imperative can be formulated in three ways, which he believed to be roughly equivalent (although many commentators do not):

• The first formulation (the Formula of Universal Law) says: "act only in accordance with that maxim through which you can at the same time will that it become a universal law."

• The second formulation (the Formula of Humanity) says: "Act that you use humanity, whether in your own person or in the person of any other, always at the same time as an end, never merely as a means."

• The third formulation (the Formula of Autonomy) is a synthesis of the previous two. It says that we should so act that we may think of ourselves as legislating universal laws through our maxims. We may think of ourselves as such autonomous legislators only insofar as we follow our own laws.

Applying the first formulation: The most popular interpretation of this formulation is called the "universalizability test," and it applies to the agent's maxim. An agent's maxim, according to Kant, is her "subjective principle of volition" -- or, in plain English, what she thinks gives her a reason to act. The universalizability test has five basic steps:

1. Find the agent's maxim.
2. Imagine a world in which everybody HAD TO follow that maxim.
3. See if a contradiction arises with that maxim in the newly imagined world.
4. If a contradiction does arise, then acting on that maxim is impermissible.
5. If there is no contradiction, then acting on that maxim is permissible (though not necessarily required).

There are two types of contradiction that Kant thinks can arise with impermissible maxims. The first type he calls "contradictions in conception." Kant uses the example of a lying promise to illustrate these. His imagined agent has the maxim: "I am going to lie so that someone will lend me money, because I am in need." Kant thinks that universalizing this maxim would lead to a contradiction -- that is, if everybody followed this maxim, and lied whenever they were in need, promises would mean nothing. So it would be contradictory (or irrational) to make a false promise to secure money, since your promise would simply be laughed at. Thus, acting on such a maxim is impermissible, and we have a duty not to make lying promises just to satisfy our needs. Incidentally, Kant believes that any maxim involving lying will lead to a contradiction, thus his infamous commitment to the view that we have a perfect (i.e. inviolable) duty not to lie.

The second type of contradiction Kant calls "contradictions in will," which arise when a universalized maxim would contradict with something the agent would have to will as a rational being. His example involves a self-reliant person who thinks everybody should mind their own business, and thus acts on the maxim: "Don't help others." In the imagined world where this is universalized, Kant thinks that this would necessarily contradict with something any rational agent must will, namely that if one is in great need and could be easily be helped by another, as a rational being he would have to will that the other person help him -- but this universalized maxim contradicts that, thus leading to a contradiction in will, and showing that the policy, "Don't help others" is impermissible. Since that is impermissible, we have a duty to (at the very least), sometimes help others.

Example of the second formulation: If I steal a book from you, I am treating you as a means (to get a book) only. If I ask to have your book, I am respecting your humanity (or ability of rational thought) and your right to say no.

Kant's most memorable quote from the Fundamentals to a Metaphysics of Morals is concerned with suicide. Kant states that, "if a man is reduced to despair by a series of misfortunes and feels and wearied of life, but is still so far in possession of his reason that he can ask himself whether it would not be contrary to his duty to himself to take his own life he should ask himself a question. He should inquire whether the maxim of his action could become a universal law of nature. His maxim is: From self-love I adopt it as a principle to shorten my life when its longer duration is likely to bring more evil than satisfaction. It is asked then simply whether this principle founded on self-love can become a universal law of nature. Now we see at once that a system of nature of which it should be a law to destroy life by means of the very feeling whose special nature it is to impel to the improvement of life would contradict itself, and therefore could not exist as a system of nature; hence the maxim cannot possibly exist as a universal law of nature, and consequently would be wholly inconsistent with the supreme principle of all duty.

The theory that we have universal duties, which hold despite one's own inclinations or the desire to pursue one's own happiness instead of these duties, is known as deontological ethics. Kant is often cited as the most important source of this strand of ethical theory (in particular, of the theory of conduct, also known as the theory of obligation).

Kant's moral philosophy has come under some criticism as his lectures on anthropology have become further studied. A small minority of critics have argued that statements such as "All races will die out except for that of the whites" [referring to the likely course of history] and that Africans are born for slavery [again referring to nature's plan rather than to what is moral--Cf., 'The human race is made for war'] (Reflexionen, 878) indicate that he does not consider non-whites to be persons in any meaningful ethical sense. This interpretation is by no means dominant. The standard account is that Kant's universalism is at times marred by incorrect empirical views of non-whites, rather than by a developed philosophical doctrine of white supremacy.

4. Further reading
Kant's most famous works are his critiques, particularly his Critique of Pure Reason, which respond to the problem of the scandal of reality, and are rooted in his reactions to David Hume and Rene Descartes, as well as Leibniz and Christian Wolff. The works of these writers forms a useful background to Kant's world and work. The work of Kant's student Fichte is also useful in understanding the process by which Kant's work was made accessible to others at that time, and for a basis for the schools of interpretation of Kant's work.

In the present the amount of literature on Kant is ever-growing. Often, the best places to start are the introductions of his translated works. Modern translations usually suggest a variety of secondary literature, the purpose of which is both to explain and to interpret Kant's philosophy.

For an example, see Christine Korsgaard's introduction to Mary Gregor's translation of the Groundwork, which not only provides a concise overview of Kant's moral philosophy, but also places his ethics within the framework of the larger critical system. Kant wrote for an audience that was familiar with medieval philosophy and the philosophy of Leibniz. The reader of today who happens not to be familiar with these parts of the philosophical tradition can be greatly hampered by lacking an adequate knowledge of technical vocabulary and historical context. Another well regarded work is Kant's Metaphysics and Theory of Science by Gottfried Martin. The English translation was published by the University of Manchester, University Press, 1955.

Contemporary historian Christine Korsgaard has published Creating the Kingdom of Ends, which provides an exigesis of Kant's view with respect to such moral systems as presented by Aristotle, Hume, and Hegel. A shorter defense and interpretation of Kant's theories is can be seen in Barbara Herman's collection of essays, The Practice of Moral Judgement. Both Korsgaard and Herman were students of John Rawls, who helped to re-invigorate Kantian ethics in the 20th century.
John Rawls' own book of published lecture notes, titled Lectures on the History of Moral Philosophy, is an excellent starting point for someone who is reading Kant for the first time. The work is particularly useful in its investigation of Kant's moral philosophy within the vicissitudes of ethical systems from Hume to Leibniz to Hegel. Two other important scholars of Kant are Henry Allison and Onora O'Neill. Both authors have written books about Kant's moral philosophy.

For an introductory account to many aspects of Kant's theoretical and practical philosophy, see The Cambridge Companion to Kant, ed. Paul Guyer. Henry Allison's book, Kant's Transcendental Idealism, provides a thorough and sympathetic account of Kant's theoretical philosophy, arguing for the centrality of "transcendental idealism" for understanding Kant. Beatrice Longuenesse's Kant and the Capacity to Judge, provides a careful, well-argued, though difficult, argument for the importance of the metaphysical deduction of the categories as well as reinterpretations of many of the central doctrines of the first Critique.

Kant's ideas have achieved some prominence in applied ethics. For example, Norman Bowie's book, Business Ethics: A Kantian Perspective, focuses on the requirement for social cooperation in a business, in which people, conceived collectively, are to be treated as a "kingdom of ends." Another example is to be found in Michael E. Berumen's book, Do No Evil: Ethics with Applications to Economic Theory and Business, which adopts a Kantian approach to making exceptions to basic moral rules, and also offers several practical examples of how ethical problems in business might be solved using Kantian analysis.

B. Immanuel Kant (1724-1804)

by Matt McCormick

Immanuel Kant is one of the most influential philosophers in the history of Western philosophy. His contributions to metaphysics, epistemology, ethics, and aesthetics have had a profound impact on almost every philosophical movement that followed him. This portion of the Encyclopedia entry will focus on his metaphysics and epistemology in one of his most important works, The Critique of Pure Reason. (All references will be to the A (1781) and B(1787) edition pages in Werner Pluhar's translation. Indianapolis: Hackett, 1996.)

A large part of Kant's work addresses the question "What can we know?" The answer, if it can be stated simply, is that our knowledge is constrained to mathematics and the science of the natural, empirical world. It is impossible, Kant argues, to extend knowledge to the supersensible realm of speculative metaphysics. The reason that knowledge has these constraints, Kant argues, is that the mind plays an active role in constituting the features of experience and limiting the mind's access to the empirical realm of space and time.

Table of Contents
Historical Background to Kant
Kant's Answers to his Predecessors
Kant's Copernican Revolution: Mind Making Nature
Kant's Transcendental Idealism
Kant's Analytic of Principles
Kant's Dialectic
The Ideas of Reason
Kant's Ethics
Reason and Freedom
The Duality of the Human Situation
The Good Will
Kant's Criticisms of Utilitarianism

Historical Background to Kant
In order to understand Kant's position, we must understand the philosophical background that he was reacting to. First, I will present a brief overview of his predecessor's positions with a brief statement of Kant's objections, then I will return to a more detailed exposition of Kant's arguments.

There are two major historical movements in the early modern period of philosophy that had a significant impact on Kant: Empiricism and Rationalism. Kant argues that both the method and the content of these philosophers' arguments contain serious flaws. A central epistemological problem for philosophers in both movements was determining how we can escape from within the confines of the human mind and the immediately knowable content of our own thoughts to acquire knowledge of the world outside of us. The Empiricists sought to accomplish this through the senses and a posteriori reasoning. The Rationalists attempted to use a priori reasoning to build the necessary bridge. A posteriori reasoning depends upon experience or contingent events in the world to provide us with information. That "Bill Clinton is president of the United States in 1999," for example, is something that I can know only through experience; I cannot determine this to be true through an analysis of the concepts of "president" or "Bill Clinton." A priori reasoning, in contrast, does not depend upon experience to inform it. The concept "bachelor" logically entails the ideas of an unmarried, adult, human male without my needing to conduct a survey of bachelors and men who are unmarried. Kant believed that this twofold distinction in kinds of knowledge was inadequate to the task of understanding metaphysics for reasons we will discuss in a moment.

Empiricists, such as Locke, Berkeley, and Hume, argued that human knowledge originates in our sensations. Locke, for instance, was a representative realist about the external world and placed great confidence in the ability of the senses to inform us of the properties that empirical objects really have in themselves. Locke had also argued that the mind is a blank slate, or a tabula rasa, that becomes populated with ideas by its interactions with the world. Experience teaches us everything, including concepts of relationship, identity, causation, and so on. Kant argues that the blank slate model of the mind is insufficient to explain the beliefs about objects that we have; some components of our beliefs must be brought by the mind to experience.

Berkeley's strict phenomenalism, in contrast to Locke, raised questions about the inference from the character of our sensations to conclusions about the real properties of mind-independent objects. Since the human mind is strictly limited to the senses for its input, Berkeley argued, it has no independent means by which to verify the accuracy of the match between sensations and the properties that objects possess in themselves. In fact, Berkeley rejected the very idea of mind-independent objects on the grounds that a mind is, by its nature, incapable of possessing an idea of such a thing. Hence, in Kant's terms, Berkeley was a material idealist. To the material idealist, knowledge of material objects is ideal or unachievable, not real. For Berkeley, mind-independent material objects are impossible and unknowable. In our sense experience we only have access to our mental representations, not to objects themselves. Berkeley argues that our judgments about objects are really judgments about these mental representations alone, not the substance that gives rise to them. In the Refutation of Material Idealism, Kant argues that material idealism is actually incompatible with a position that Berkeley held, namely that we are capable of making judgments about our experience.

David Hume pursued Berkeley's empirical line of inquiry even further, calling into question even more of our common sense beliefs about the source and support of our sense perceptions. Hume maintains that we cannot provide a priori or a posteriori justifications for a number of our beliefs like, "Objects and subjects persist identically over time," or "Every event must have a cause." In Hume's hands, it becomes clear that empiricism cannot give us an epistemological justification for the claims about objects, subjects, and causes that we took to be most obvious and certain about the world.

Kant expresses deep dissatisfaction with the idealistic and seemingly skeptical results of the empirical lines of inquiry. In each case, Kant gives a number of arguments to show that Locke's, Berkeley's, and Hume's empiricist positions are untenable because they necessarily presupposes the very claims they set out to disprove. In fact, any coherent account of how we perform even the most rudimentary mental acts of self-awareness and making judgments about objects must presuppose these claims, Kant argues. Hence, while Kant is sympathetic with many parts of empiricism, ultimately it cannot be a satisfactory account of our experience of the world.

The Rationalists, principally Descartes, Spinoza, and Leibniz, approached the problems of human knowledge from another angle. They hoped to escape the epistemological confines of the mind by constructing knowledge of the external world, the self, the soul, God, ethics, and science out of the simplest, indubitable ideas possessed innately by the mind. Leibniz in particular, thought that the world was knowable a priori, through an analysis of ideas and derivations done through logic. Supersensible knowledge, the Rationalists argued, can be achieved by means of reason. Descartes believed that certain truths, that "if I am thinking, I exist," for example, are invulnerable to the most pernicious skepticism. Armed with the knowledge of his own existence, Descartes hoped to build a foundation for all knowledge.

Kant's Refutation of Material Idealism works against Descartes' project as well as Berkeley's. Descartes believed that he could infer the existence of objects in space outside of him based on his awareness of his own existence coupled with an argument that God exists and is not deceiving him about the evidence of his senses. Kant argues in the Refutation chapter that knowledge of external objects cannot be inferential. Rather, the capacity to be aware of one's own existence in Descartes' famous cogito argument already presupposes that existence of objects in space and time outside of me.

Kant had also come to doubt the claims of the Rationalists because of what he called Antinomies, or contradictory, but validly proven pairs of claims that reason is compelled toward. From the basic principles that the Rationalists held, it is possible, Kant argues, to prove conflicting claims like, "The world has a beginning in time and is limited as regards space," and "The world has no beginning, and no limits in space." (A 426/B 454) Kant claims that antinomies like this one reveal fundamental methodological and metaphysical mistakes in the rationalist project. The contradictory claims could both be proven because they both shared the mistaken metaphysical assumption that we can have knowledge of things as they are in themselves, independent of the conditions of our experience of them.

The Antinomies can be resolved, Kant argues, if we understand the proper function and domain of the various faculties that contribute to produce knowledge. We must recognize that we cannot know things as they are in themselves and that our knowledge is subject to the conditions of our experience. The Rationalist project was doomed to failure because it did not take note of the contribution that our faculty of reason makes to our experience of objects. Their a priori analysis of our ideas could inform us about the content of our ideas, but it could not give a coherent demonstration of metaphysical truths about the external world, the self, the soul, God, and so on.

Kant's Answers to his Predecessors
Kant's answer to the problems generated by the two traditions mentioned above changed the face of philosophy. First, Kant argued that that old division between a priori truths and a posteriori truths employed by both camps was insufficient to describe the sort of metaphysical claims that were under dispute. An analysis of knowledge also requires a distinction between synthetic and analytic truths. In an analytic claim, the predicate is contained within the subject. In the claim, "Every body occupies space," the property of occupying space is revealed in an analysis of what it means to be a body. The subject of a synthetic claim, however, does not contain the predicate. In, "This tree is 120 feet tall," the concepts are synthesized or brought together to form a new claim that is not contained in any of the individual concepts. The Empiricists had not been able to prove synthetic a priori claims like "Every event must have a cause," because they had conflated "synthetic" and "a posteriori" as well as "analytic" and "a priori." Then they had assumed that the two resulting categories were exhaustive. A synthetic a priori claim, Kant argues, is one that must be true without appealing to experience, yet the predicate is not logically contained within the subject, so it is no surprise that the Empiricists failed to produce the sought after justification. The Rationalists had similarly conflated the four terms and mistakenly proceeded as if claims like, "The self is a simple substance," could be proven analytically and a priori.

Synthetic a priori claims, Kant argues, demand an entirely different kind of proof than those required for analytic, a priori claims or synthetic, a posteriori claims. Indications for how to proceed, Kant says, can be found in the examples of synthetic a priori claims in natural science and mathematics, specifically geometry. Claims like Newton's, "the quantity of matter is always preserved," and the geometer's claim, "the angles of a triangle always add up to 180 degrees" are known a priori, but they cannot be known merely from an analysis of the concepts of matter or triangle. We must "go outside and beyond the concept. . . joining to it a priori in thought something which I have not thought in it." (B 18) A synthetic a priori claim constructs upon and adds to what is contained analytically in a concept without appealing to experience. So if we are to solve the problems generated by Empiricism and Rationalism, the central question of metaphysics in the Critique of Pure Reason reduces to "How are synthetic a priori judgments possible?" (19) If we can answer that question, then we can determine the possibility, legitimacy, and range of all metaphysical claims.

Kant's Copernican Revolution: Mind Making Nature
Kant's answer to the question is complicated, but his conclusion is that a number of synthetic a priori claims, like those from geometry and the natural sciences, are true because of the structure of the mind that knows them. "Every event must have a cause" cannot be proven by experience, but experience is impossible without it because it describes the way the mind must necessarily order its representations. We can understand Kant's argument again by considering his predecessors.

According to the Rationalist and Empiricist traditions, the mind is passive either because it finds itself possessing innate, well-formed ideas ready for analysis, or because it receives ideas of objects into a kind of empty theater, or blank slate. Kant's crucial insight here is to argue that experience of a world as we have it is only possible if the mind provides a systematic structuring of its representations. This structuring is below the level of, or logically prior to, the mental representations that the Empiricists and Rationalists analyzed. Their epistemological and metaphysical theories could not adequately explain the sort of judgments or experience we have because they only considered the results of the mind's interaction with the world, not the nature of the mind's contribution. Kant's methodological innovation was to employ what he calls a transcendental argument to prove synthetic a priori claims. Typically, a transcendental argument attempts to prove a conclusion about the necessary structure of knowledge on the basis of an incontrovertible mental act. Kant argues in the Refutation of Material Idealism that "There are objects that exist in space and time outside of me," (B 274) which cannot be proven by a priori or a posteriori methods, is a necessary condition of the possibility of being aware of one's own existence. It would not be possible to be aware of myself as existing, he says, without presupposing the existing of something permanent outside of me to distinguish myself from. I am aware of myself as existing. Therefore, there is something permanent outside of me.

This argument is one of many transcendental arguments that Kant gives that focuses on the contribution that the mind itself makes to its experience. These arguments lead Kant to conclude that the Empiricists' assertion that experience is the source of all our ideas. It must be the mind's structuring, Kant argues, that makes experience possible. If there are features of experience that the mind brings to objects rather than given to the mind by objects, that would explain why they are indispensable to experience but unsubstantiated in it. And that would explain why we can give a transcendental argument for the necessity of these features. Kant thought that Berkeley and Hume identified at least part of the mind's a priori contribution to experience with the list of claims that they said were unsubstantiated on empirical grounds: "Every event must have a cause," "There are mind-independent objects that persist over time," and "Identical subjects persist over time." The empiricist project must be incomplete since these claims are necessarily presupposed in our judgments, a point Berkeley and Hume failed to see. So, Kant argues that a philosophical investigation into the nature of the external world must be as much an inquiry into the features and activity of the mind that knows it.

The idea that the mind plays an active role in structuring reality is so familiar to us now that it is difficult for us to see what a pivotal insight this was for Kant. He was well aware of the idea's power to overturn the philosophical worldviews of his contemporaries and predecessors, however. He even somewhat immodestly likens his situation to that of Copernicus in revolutionizing our worldview. On the Lockean view, mental content is given to the mind by the objects in the world. Their properties migrate into the mind, revealing the true nature of objects. Kant says, "Thus far it has been assumed that all our cognition must conform to objects" (B xvi). But that approach cannot explain why some claims like, "every event must have a cause," are a priori true. Similarly, Copernicus recognized that the movement of the stars cannot be explained by making them revolve around the observer; it is the observer that must be revolving. Analogously, Kant argued that we must reformulate the way we think about our relationship to objects. It is the mind itself which gives objects at least some of their characteristics because they must conform to its structure and conceptual capacities. Thus, the mind's active role in helping to create a world that is experiencable must put it at the center of our philosophical investigations. The appropriate starting place for any philosophical inquiry into knowledge, Kant decides, is with the mind that can have that knowledge.

Kant's critical turn toward the mind of the knower is ambitious and challenging. Kant has rejected the dogmatic metaphysics of the Rationalists that promises supersensible knowledge. And he has argued that Empiricism faces serious limitations. His transcendental method will allow him to analyze the metaphysical requirements of the empirical method without venturing into speculative and ungrounded metaphysics. In this context, determining the "transcendental" components of knowledge means determining, "all knowledge which is occupied not so much with objects as with the mode of our knowledge of objects in so far as this mode of knowledge is to be possible a priori." (A 12/B 25)

The project of the Critique of Pure Reason is also challenging because in the analysis of the mind's transcendental contributions to experience we must employ the mind, the only tool we have, to investigate the mind. We must use the faculties of knowledge to determine the limits of knowledge, so Kant's Critique of Pure Reason is both a critique that takes pure reason as its subject matter, and a critique that is conducted by pure reason.

Kant's argument that the mind makes an a priori contribution to experiences should not be mistaken for an argument like the Rationalists' that the mind possesses innate ideas like, "God is a perfect being." Kant rejects the claim that there are complete propositions like this one etched on the fabric of the mind. He argues that the mind provides a formal structuring that allows for the conjoining of concepts into judgments, but that structuring itself has no content. The mind is devoid of content until interaction with the world actuates these formal constraints. The mind possesses a priori templates for judgments, not a priori judgments.

Kant's Transcendental Idealism
With Kant's claim that the mind of the knower makes an active contribution to experience of objects before us, we are in a better position to understand transcendental idealism. Kant's arguments are designed to show the limitations of our knowledge. The Rationalists believed that we could possess metaphysical knowledge about God, souls, substance, and so; they believed such knowledge was transcendentally real. Kant argues, however, that we cannot have knowledge of the realm beyond the empirical. That is, transcendental knowledge is ideal, not real, for minds like ours. Kant identifies two a priori sources of these constraints. The mind has a receptive capacity, or the sensibility, and the mind possesses a conceptual capacity, or the understanding.

In the Transcendental Aesthetic section of the Critique, Kant argues that sensibility is the understanding's means of accessing objects. The reason synthetic a priori judgments are possible in geometry, Kant argues, is that space is an a priori form of sensibility. That is, we can know the claims of geometry with a priori certainty (which we do) only if experiencing objects in space is the necessary mode of our experience. Kant also argues that we cannot experience objects without being able to represent them spatially. It is impossible to grasp an object as an object unless we delineate the region of space it occupies. Without a spatial representation, our sensations are undifferentiated and we cannot ascribe properties to particular objects. Time, Kant argues, is also necessary as a form or condition of our intuitions of objects. The idea of time itself cannot be gathered from experience because succession and simultaneity of objects, the phenomena that would indicate the passage of time, would be impossible to represent if we did not already possess the capacity to represent objects in time.

Another way to understand Kant's point here is that it is impossible for us to have any experience of objects that are not in time and space. Furthermore, space and time themselves cannot be perceived directly, so they must be the form by which experience of objects is had. A consciousness that apprehends objects directly, as they are in themselves and not by means of space and time, is possible--God, Kant says, has a purely intuitive consciousness--but our apprehension of objects is always mediated by the conditions of sensibility. Any discursive or concept using consciousness (A 230/B 283) like ours must apprehend objects as occupying a region of space and persisting for some duration of time.

Subjecting sensations to the a priori conditions of space and time is not sufficient to make judging objects possible. Kant argues that the understanding must provide the concepts, which are rules for identifying what is common or universal in different representations.(A 106) He says, "without sensibility no object would be given to us; and without understanding no object would be thought. Thoughts without content are empty; intuitions without concepts are blind." (B 75) Locke's mistake was believing that our sensible apprehensions of objects are thinkable and reveal the properties of the objects themselves. In the Analytic of Concepts section of the Critique, Kant argues that in order to think about the input from sensibility, sensations must conform to the conceptual structure that the mind has available to it. By applying concepts, the understanding takes the particulars that are given in sensation and identifies what is common and general about them. A concept of "shelter" for instance, allows me to identify what is common in particular representations of a house, a tent, and a cave.

The empiricist might object at this point by insisting that such concepts do arise from experience, raising questions about Kant's claim that the mind brings an a priori conceptual structure to the world. Indeed, concepts like "shelter" do arise partly from experience. But Kant raises a more fundamental issue. An empirical derivation is not sufficient to explain all of our concepts. As we have seen, Hume argued, and Kant accepts, that we cannot empirically derive our concepts of causation, substance, self, identity, and so forth. What Hume had failed to see, Kant argues, is that even the possibility of making judgments about objects, to which Hume would assent, presupposes the possession of these fundamental concepts. Hume had argued for a sort of associationism to explain how we arrive at causal beliefs. My idea of a moving cue ball, becomes associated with my idea of the eight ball that is struck and falls into the pocket. Under the right circumstances, repeated impressions of the second following the first produces a belief in me that the first causes the second.

The problem that Kant points out is that a Humean association of ideas already presupposes that we can conceive of identical, persistent objects that have regular, predictable, causal behavior. And being able to conceive of objects in this rich sense presupposes that the mind makes several a priori contributions. I must be able to separate the objects from each other in my sensations, and from my sensations of myself. I must be able to attribute properties to the objects. I must be able to conceive of an external world with its own course of events that is separate from the stream of perceptions in my consciousness. These components of experience cannot be found in experience because they constitute it. The mind's a priori conceptual contribution to experience can be enumerated by a special set of concepts that make all other empirical concepts and judgments possible. These concepts cannot be experienced directly; they are only manifest as the form which particular judgments of objects take. Kant believes that formal logic has already revealed what the fundamental categories of thought are. The special set of concepts is Kant's Table of Categories, which are taken mostly from Aristotle with a few revisions:

Of Quantity




Of Quality




Of Relation

Inherence and Subsistence

Casuality and Dependence


Of Modality

Possibility - Impossibility

Existence - Nonexistence

Necessity - Contingency

While Kant does not give a formal derivation of it, he believes that this is the complete and necessary list of the a priori contributions that the understanding brings to its judgments of the world. Every judgment that the understanding can make must fall under the table of categories. And subsuming spatiotemporal sensations under the formal structure of the categories makes judgments, and ultimately knowledge, of empirical objects possible.

Since objects can only be experienced spatiotemporally, the only application of concepts that yields knowledge is to the empirical, spatiotemporal world. Beyond that realm, there can be no sensations of objects for the understanding to judge, rightly or wrongly. Since intuitions of the physical world are lacking when we speculate about what lies beyond, metaphysical knowledge, or knowledge of the world outside the physical, is impossible. Claiming to have knowledge from the application of concepts beyond the bounds of sensation results in the empty and illusory transcendent metaphysics of Rationalism that Kant reacts against.

It should be pointed out, however, that Kant is not endorsing an idealism about objects like Berkeley's. That is, Kant does not believe that material objects are unknowable or impossible. While Kant is a transcendental idealist--he believes the nature of objects as they are in themselves is unknowable to us--knowledge of appearances is nevertheless possible. As noted above, in The Refutation of Material Idealism, Kant argues that the ordinary self-consciousness that Berkeley and Descartes would grant implies "the existence of objects in space outside me." (B 275) Consciousness of myself would not be possible if I were not able to make determinant judgments about objects that exist outside of me and have states that are independent of the of my inner experience. Another way to put the point is to say that the fact that the mind of the knower makes the a priori contribution does not mean that space and time or the categories are mere figments of the imagination. Kant is an empirical realist about the world we experience; we can know objects as they appear to us. He gives a robust defense of science and the study of the natural world from his argument about the mind's role in making nature. All discursive, rational beings must conceive of the physical world as spatially and temporally unified, he argues. And the table of categories is derived from the most basic, universal forms of logical inference, Kant believes. Therefore, it must be shared by all rational beings. So those beings also share judgments of an intersubjective, unified, public realm of empirical objects. Hence, objective knowledge of the scientific or natural world is possible. Indeed, Kant believes that the examples of Newton and Galileo show it is actual. So Berkeley's claims that we do not know objects outside of us and that such knowledge is impossible are both mistaken.

In conjunction with his analysis of the possibility of knowing empirical objects, Kant gives an analysis of the knowing subject that has sometimes been called his transcendental psychology. Much of Kant's argument can be seen as subjective, not because of variations from mind to mind, but because the source of necessity and universality is in the mind of the knowing subject, not in objects themselves. Kant draws several conclusions about what is necessarily true of any consciousness that employs the faculties of sensibility and understanding to produce empirical judgments. As we have seen, a mind that employs concepts must have a receptive faculty that provides the content of judgments. Space and time are the necessary forms of apprehension for the receptive faculty. The mind that has experience must also have a faculty of combination or synthesis, the imagination for Kant, that apprehends the data of sense, reproduces it for the understanding, and recognizes their features according to the conceptual framework provided by the categories. The mind must also have a faculty of understanding that provides empirical concepts and the categories for judgment. The various faculties that make judgment possible must be unified into one mind. And it must be identical over time if it is going to apply its concepts to objects over time. Kant here addresses Hume's famous assertion that introspection reveals nothing more than a bundle of sensations that we group together and call the self. Judgments would not be possible, Kant maintains, if the mind that senses is not the same as the mind that possesses the forms of sensibility. And that mind must be the same as the mind that employs the table of categories, that contributes empirical concepts to judgment, and that synthesizes the whole into knowledge of a unified, empirical world. So the fact that we can empirically judge proves, contra Hume, that the mind cannot be a mere bundle of disparate introspected sensations. In his works on ethics Kant will also argue that this mind is the source of spontaneous, free, and moral action. Kant believes that all the threads of his transcendental philosophy come together in this "highest point" which he calls the transcendental unity of apperception.

Kant's Analytic of Principles
We have seen the progressive stages of Kant's analysis of the faculties of the mind which reveals the transcendental structuring of experience performed by these faculties. First, in his analysis of sensibility, he argues for the necessarily spatiotemporal character of sensation. Then Kant analyzes the understanding, the faculty that applies concepts to sensory experience. He concludes that the categories provide a necessary, foundational template for our concepts to map onto our experience. In addition to providing these transcendental concepts, the understanding also is the source of ordinary empirical concepts that make judgments about objects possible. The understanding provides concepts as the rules for identifying the properties in our representations.
Kant's next concern is with the faculty of judgment, "If understanding as such is explicated as our power of rules, then the power of judgment is the ability to subsume under rules, i.e., to distinguish whether something does or does not fall under a given rule." (A 132/B 172). The next stage in Kant's project will be to analyze the formal or transcendental features of experience that enable judgment, if there are any such features besides what the previous stages have identified. The cognitive power of judgment does have a transcendental structure. Kant argues that there are a number of principles that must necessarily be true of experience in order for judgment to be possible. Kant's analysis of judgment and the arguments for these principles are contained in his Analytic of Principles.

Within the Analytic, Kant first addresses the challenge of subsuming particular sensations under general categories in the Schematism section. Transcendental schemata, Kant argues, allow us to identify the homogeneous features picked out by concepts from the heterogeneous content of our sensations. Judgment is only possible if the mind can recognize the components in the diverse and disorganized data of sense that make those sensations an instance of a concept or concepts. A schema makes it possible, for instance, to subsume the concrete and particular sensations of an Airedale, a Chihuahua, and a Labrador all under the more abstract concept "dog."

The full extent of Kant's Copernican revolution becomes even more clear in the rest of the Analytic of Principles. That is, the role of the mind in making nature is not limited to space, time, and the categories. In the Analytic of Principles, Kant argues that even the necessary conformity of objects to natural law arises from the mind. Thus far, Kant's transcendental method has permitted him to reveal the a priori components of sensations, the a priori concepts. In the sections titled the Axioms, Anticipations, Analogies, and Postulates, he argues that there are a priori judgments that must necessarily govern all appearances of objects. These judgments are a function of the table of categories' role in determining all possible judgments, so the four sections map onto the four headings of that table. I include all of the a priori judgments, or principles, here to illustrate the earlier claims about Kant's empirical realism, and to show the intimate relationship Kant saw between his project and that of the natural sciences:

Axioms of Intuition

All intuitions are extensive magnitudes.

Anticipations of Perceptions

In all appearances the real that is an object of sensation has intensive magnitude, i.e., a degree.

Analogies of Experience

In all variations by appearances substance is permanent, and its quantum in nature is neither increased nor decreased.

All changes occur according to the law of the connection of cause and effect.

All substances, insofar as they can be perceived in space as simultaneous, are in thoroughgoing interaction.

Postulates of Empirical Thought

What agrees (in terms of intuition and concepts) with the formal conditions of experience is possible.

What coheres with the material conditions of experience (with sensation) is actual.

That whose coherence with the actual is determined according to universal conditions of experience is necessary (exists necessarily)

Kant's Dialectic
The discussion of Kant's metaphysics and epistemology so far (including the Analytic of Principles)has been confined primarily to the section of the Critique of Pure Reason that Kant calls the Transcendental Analytic. The purpose of the Analytic, we are told, is "the rarely attempted dissection of the power of the understanding itself." (A 65/B 90). Kant's project has been to develop the full argument for his theory about the mind's contribution to knowledge of the world. Once that theory is in place, we are in a position to see the errors that are caused by transgressions of the boundaries to knowledge established by Kant's transcendental idealism and empirical realism. Kant calls judgments that pretend to have knowledge beyond these boundaries and that even require us to tear down the limits that he has placed on knowledge, transcendent judgments. The Transcendental Dialectic section of the book is devoted to uncovering the illusion of knowledge created by transcendent judgments and explaining why the temptation to believe them persists.

Kant argues that the proper functioning of the faculties of sensibility and the understanding combine to draw reason, or the cognitive power of inference, inexorably into mistakes. The faculty of reason naturally seeks the highest ground of unconditional unity. It seeks to unify and subsume all particular experiences under higher and higher principles of knowledge. But sensibility cannot by its nature provide the intuitions that would make knowledge of the highest principles and of things as they are in themselves possible. Nevertheless, reason, in its function as the faculty of inference, inevitably draws conclusions about what lies beyond the boundaries of sensibility. The unfolding of this conflict between the faculties reveals more about the mind's relationship to the world it seeks to know and the possibility of a science of metaphysics.

Kant believes that Aristotle's logic of the syllogism captures the logic employed by reason. The resulting mistakes from the inevitable conflict between sensibility and reason reflect the logic of Aristotle's syllogism. Corresponding to the three basic kinds of syllogism are three dialectic mistakes or illusions of transcendent knowledge that cannot be real. Kant's discussion of these three classes of mistakes are contained in the Paralogisms, the Antinomies, and the Ideals of Reason. The Dialectic explains the illusions of reason in these sections. But since the illusions arise from the structure of our faculties, they will not cease to have their influence on our minds any more than we can prevent the moon from seeming larger when it is on the horizon than when it is overhead. (A 297/B 354).

In the Paralogisms, Kant argues that a failure to recognize the difference between appearances and things in themselves, particularly in the case of the introspected self, lead us into transcendent error. Kant argues against several conclusions encouraged by Descartes and the rational psychologists, who believed they could build human knowledge from the "I think" of the cogito argument. From the "I think" of self-awareness we can infer, they maintain, that the self or soul is 1) simple, 2) immaterial, 3) an identical substance and 4) that we perceive it directly, in contrast to external objects whose existence is merely possible. That is, the rational psychologists claimed to have knowledge of the self as transcendentally real. Kant believes that it is impossible to demonstrate any of these four claims, and that the mistaken claims to knowledge stem from a failure to see the real nature of our apprehension of the "I." Reason cannot fail to apply the categories to its judgments of the self, and that application gives rise to these four conclusions about the self that correspond roughly to the four headings in the table of categories. But to take the self as an object of knowledge here is to pretend to have knowledge of the self as it is in itself, not as it appears to us. Our representation of the "I" itself is empty. It is subject to the condition of inner sense, time, but not the condition of outer sense, space, so it cannot be a proper object of knowledge. It can be thought through concepts, but without the commensurate spatial and temporal intuitions, it cannot be known. Each of the four paralogisms explains the categorical structure of reason that led the rational psychologists to mistake the self as it appears to us for the self as it is in itself.

We have already mentioned the Antinomies, in which Kant analyzes the methodological problems of the Rationalist project. Kant sees the Antinomies as the unresolved dialogue between skepticism and dogmatism about knowledge of the world. There are four antinomies, again corresponding to the four headings of the table of categories, that are generated by reason's attempts to achieve complete knowledge of the realm beyond the empirical. Each antinomy has a thesis and an antithesis, both of which can be validly proven, and since each makes a claim that is beyond the grasp of spatiotemporal sensation, neither can be confirmed or denied by experience. The First Antinomy argues both that the world has a beginning in time and space, and no beginning in time and space. The Second Antinomy's arguments are that every composite substance is made of simple parts and that nothing is composed of simple parts. The Third Antinomy's thesis is that agents like ourselves have freedom and its antithesis is that they do not. The Fourth Antinomy contains arguments both for and against the existence of a necessary being in the world. The seemingly irreconcilable claims of the Antinomies can only be resolved by seeing them as the product of the conflict of the faculties and by recognizing the proper sphere of our knowledge in each case. In each of them, the idea of "absolute totality, which holds only as a condition of things in themselves, has been applied to appearances" (A 506/B534).

The result of Kant's analysis of the Antinomies is that we can reject both claims of the first two and accept both claims of the last two, if we understand their proper domains. In the first Antinomy, the world as it appears to us is neither finite since we can always inquire about its beginning or end, nor is it infinite because finite beings like ourselves cannot cognize an infinite whole. As an empirical object, Kant argues, it is indefinitely constructible for our minds. As it is in itself, independent of the conditions of our thought, should not be identified as finite or infinite since both are categorial conditions of our thought. Kant's resolution of the third Antinomy (A 445/B 473) clarifies his position on freedom. He considers the two competing hypotheses of speculative metaphysics that there are different types of causality in the world: 1) there are natural causes which are themselves governed by the laws of nature as well as uncaused causes like ourselves that can act freely, or 2) the causal laws of nature entirely govern the world including our actions. The conflict between these contrary claims can be resolved, Kant argues, by taking his critical turn and recognizing that it is impossible for any cause to be thought of as uncaused itself in the realm of space and time. But reason, in trying to understand the ground of all things, strives to unify its knowledge beyond the empirical realm. The empirical world, considered by itself, cannot provide us with ultimate reasons. So if we do not assume a first or free cause we cannot completely explain causal series in the world. So for the Third Antinomy, as for all of the Antinomies, the domain of the Thesis is the intellectual, rational, noumenal world. The domain of the Antithesis is the spatiotemporal world.

The Ideas of Reason
The faculty of reason has two employments. For the most part, we have engaged in an analysis of theoretical reason which has determined the limits and requirements of the employment of the faculty of reason to obtain knowledge. Theoretical reason, Kant says, makes it possible to cognize what is. But reason has its practical employment in determining what ought to be as well. (A 633/B 661) This distinction roughly corresponds to the two philosophical enterprises of metaphysics and ethics. Reason's practical use is manifest in the regulative function of certain concepts that we must think with regard to the world, even though we can have no knowledge of them.
Kant believes that, "Human reason is by its nature architectonic." (A 474/B 502). That is, reason thinks of all cognitions as belonging to a unified and organized system. Reason is our faculty of making inferences and of identifying the grounds behind every truth. It allows us to move from the particular and contingent to the global and universal. I infer that "Caius is mortal" from the fact that "Caius is a man" and the universal claim, "All men are mortal." In this fashion, reason seeks higher and higher levels of generality in order to explain the way things are. In a different kind of example, the biologist's classification of every living thing into a kingdom, phylum, class, order, family, genus, and species, illustrates reason's ambition to subsume the world into an ordered, unified system. The entire empirical world, Kant argues, must be conceived of by reason as causally necessitated (as we saw in the Analogies). We must connect, "one state with a previous state upon which the state follows according to a rule." Each cause, and each cause's cause, and each additional ascending cause must itself have a cause. Reason generates this hierarchy that combines to provide the mind with a conception of a whole system of nature. Kant believes that it is part of the function of reason to strive for a complete, determinate understanding of the natural world. But our analysis of theoretical reason has made it clear that we can never have knowledge of the totality of things because we cannot have the requisite sensations of the totality, hence one of the necessary conditions of knowledge is not met. Nevertheless, reason seeks a state of rest from the regression of conditioned, empirical judgments in some unconditioned ground that can complete the series (A 584/B 612). Reason's structure pushes us to accept certain ideas of reason that allow completion of its striving for unity. We must assume the ideas of God, freedom, and immortality, Kant says, not as objects of knowledge, but as practical necessities for the employment of reason in the realm where we can have knowledge. By denying the possibility of knowledge of these ideas, yet arguing for their role in the system of reason, Kant had to, "annul knowledge in order to make room for faith." (B xxx).

Kant's Ethics
It is rare for a philosopher in any era to make a significant impact on any single topic in philosophy. For a philosopher to impact as many different areas as Kant did is extraordinary. His ethical theory has been as, if not more, influential than his work in epistemology and metaphysics. Most of Kant's work on ethics is presented in two works. The Foundations of the Metaphysics of Morals (1785) is Kant's "search for and establishment of the supreme principle of morality." In The Critique of Practical Reason (1787) Kant attempts to unify his account of practical reason with his work in the Critique of Pure Reason. Kant is the primary proponent in history of what is called deontological ethics. Deontology is the study of duty. On Kant's view, the sole feature that gives an action moral worth is not the outcome that is achieved by the action, but the motive that is behind the action. The categorical imperative is Kant's famous statement of this duty: "Act only according to that maxim by which you can at the same time will that it should become a universal law."

Reason and Freedom
For Kant, as we have seen, the drive for total, systematic knowledge in reason can only be fulfilled with assumptions that empirical observation cannot support. The metaphysical facts about the ultimate nature of things in themselves must remain a mystery to us because of the spatiotemporal constraints on sensibility. When we think about the nature of things in themselves or the ultimate ground of the empirical world, Kant has argued that we are still constrained to think through the categories, we cannot think otherwise, but we can have no knowledge because sensation provides our concepts with no content. So, reason is put at odds with itself because it is constrained by the limits of its transcendental structure, but it seeks to have complete knowledge that would take it beyond those limits.

Freedom plays a central role in Kant's ethics because the possibility of moral judgments presupposes it. Freedom is an idea of reason that serves an indispensable practical function. Without the assumption of freedom, reason cannot act. If we think of ourselves as completely causally determined, and not as uncaused causes ourselves, then any attempt to conceive of a rule that prescribes the means by which some end can be achieved is pointless. I cannot both think of myself as entirely subject to causal law and as being able to act according to the conception of a principle that gives guidance to my will. We cannot help but think of our actions as the result of an uncaused cause if we are to act at all and employ reason to accomplish ends and understand the world.

So reason has an unavoidable interest in thinking of itself as free. That is, theoretical reason cannot demonstrate freedom, but practical reason must assume for the purpose of action. Having the ability to make judgments and apply reason puts us outside that system of causally necessitated events. "Reason creates for itself the idea of a spontaneity that can, on its own, start to act--without, i.e., needing to be preceded by another cause by means of which it is determined to action in turn, according to the law of causal connection," Kant says. (A 533/B 561) In its intellectual domain, reason must think of itself as free.

It is dissatisfying that he cannot demonstrate freedom, nevertheless, it comes as no surprise that we must think of ourselves as free. In a sense, Kant is agreeing with the common sense view that how I choose to act makes a difference in how I actually act. Even if it were possible to give a predictive empirical account of why I act as I do, say on the grounds of a functionalist psychological theory, those considerations would mean nothing to me in my deliberations. When I make a decision about what to do, about which car to buy, for instance, the mechanism at work in my nervous system makes no difference to me. I still have to peruse Consumer Reports, consider my options, reflect on my needs, and decide on the basis of the application of general principles. My first person perspective is unavoidable, hence the deliberative, intellectual process of choice is unavoidable.

The Duality of the Human Situation
The question of moral action is not an issue for two classes of beings, according to Kant. The animal consciousness, the purely sensuous being, is entirely subject to causal determination. It is part of the causal chains of the empirical world, but not an originator of causes the way humans are. Hence, rightness or wrongness, as concepts that apply to situations one has control over, do not apply. We do not morally fault the lion for killing the gazelle, or even for killing its own young. The actions of a purely rational being, by contrast, are in perfect accord with moral principles, Kant says. There is nothing in such a being's nature to make it falter. Its will always conforms with the dictates of reason. Humans are between the two worlds. We are both sensible and intellectual, as was pointed out in the discussion of the first Critique. We are neither wholly determined to act by natural impulse, nor are we free of non-rational impulse. Hence we need rules of conduct. We need, and reason is compelled to provide, a principle that declares how we ought to act when it is in our power to choose

Since we find ourselves in the situation of possessing reason, being able to act according to our own conception of rules, there is a special burden on us. Other creatures are acted upon by the world. But having the ability to choose the principle to guide our actions makes us actors. We must exercise our will and our reason to act. Will is the capacity to act according to the principles provided by reason. Reason assumes freedom and conceives of principles of action in order to function.

Two problems face us however. First, we are not wholly rational beings, so we are liable to succumb to our non-rational impulses. Second, even when we exercise our reason fully, we often cannot know which action is the best. The fact that we can choose between alternate courses of actions (we are not determined to act by instinct or reason) introduces the possibility that there can be better or worse ways of achieving our ends and better or worse ends, depending upon the criteria we adopt. The presence of two different kinds of object in the world adds another dimension, a moral dimension, to our deliberations. Roughly speaking, we can divide the world into beings with reason and will like ourselves and things that lack those faculties. We can think of these classes of things as ends-in-themselves and mere means-to-ends, respectively.

Ends-in-themselves are autonomous beings with their own agendas; failing to recognize their capacity to determine their own actions would be to thwart their freedom and undermine reason itself. When we reflect on alternative courses of action, means-to-ends, things like buildings, rocks, and trees, deserve no special status in our deliberations about what goals we should have and what means we use to achieve them. The class of ends-in-themselves, reasoning agents like ourselves, however, do have a special status in our considerations about what goals we should have and the means we employ to accomplish them. Moral actions, for Kant, are actions where reason leads, rather than follows, and actions where we must take other beings that act according to their own conception of the law, into account.

The Good Will
The will, Kant says, is the faculty of acting according to a conception of law. When we act, whether or not we achieve what we intend with our actions is often beyond our control, so the morality of our actions does not depend upon their outcome. What we can control, however, is the will behind the action. That is, we can will to act according to one law rather than another. The morality of an action, therefore, must be assessed in terms of the motivation behind it. If two people, Smith and Jones, perform the same act, from the same conception of the law, but events beyond Smith's control prevent her from achieving her goal, Smith is not less praiseworthy for not succeeding. We must consider them on equal moral ground in terms of the will behind their actions.

The only thing that is good without qualification is the good will, Kant says. All other candidates for an intrinsic good have problems, Kant argues. Courage, health, and wealth can all be used for ill purposes, Kant argues, and therefore cannot be intrinsically good. Happiness is not intrinsically good because even being worthy of happiness, Kant says, requires that one possess a good will. The good will is the only unconditional good despite all encroachments. Misfortune may render someone incapable of achieving her goals, for instance, but the goodness of her will remains.

Goodness cannot arise from acting on impulse or natural inclination, even if impulse coincides with duty. It can only arise from conceiving of one's actions in a certain way. A shopkeeper, Kant says, might do what is in accord with duty and not overcharge a child. Kant argues, "it is not sufficient to do that which should be morally good that it conform to the law; it must be done for the sake of the law." (Foundations of the Metaphysics of Morals, Akademie pagination 390) There is a clear moral difference between the shopkeeper that does it for his own advantage to keep from offending other customers and the shopkeeper who does it from duty and the principle of honesty.(Ibid., 398) Likewise, in another of Kant's carefully studied examples, the kind act of the person who overcomes a natural lack of sympathy for other people out of respect for duty has moral worth, whereas the same kind act of the person who naturally takes pleasure in spreading joy does not. A person's moral worth cannot be dependent upon what nature endowed them with accidentally. The selfishly motivated shopkeeper and the naturally kind person both act on equally subjective and accidental grounds. What matters to morality is that the actor think about their actions in the right manner.
We might be tempted to think that the motivation that makes an action good is having a positive goal--to make people happy, or to provide some benefit. But that is not the right sort of motive, Kant says. No outcome, should we achieve it, can be unconditionally good. Fortune can be misused, what we thought would induce benefit might actually bring harm, and happiness might be undeserved. Hoping to achieve some particular end, no matter how beneficial it may seem, is not purely and unconditionally good. It is not the effect or even the intended effect that bestows moral character on an action. All intended effects "could be brought about through other causes and would not require the will of a rational being, while the highest and unconditional good can be found only in such a will." (Ibid., 401) It is the possession of a rationally guided will that adds a moral dimension to one's acts. So it is the recognition and appreciation of duty itself that must drive our actions.

What is the duty that is to motivate our actions and to give them moral value? Kant distinguishes two kinds of law produced by reason. Given some end we wish to achieve, reason can provide a hypothetical imperative, or rule of action for achieving that end. A hypothetical imperative says that if you wish to buy a new car, then you must determine what sort of cars are available for purchase. Conceiving of a means to achieve some desired end is by far the most common employment of reason. But Kant has shown that the acceptable conception of the moral law cannot be merely hypothetical. Our actions cannot be moral on the ground of some conditional purpose or goal. Morality requires an unconditional statement of one's duty.

And in fact, reason produces an absolute statement of moral action. The moral imperative is unconditional; that is, its imperative force is not tempered by the conditional "if I want to achieve some end, then do X." It simply states, do X. Kant believes that reason dictates a categorical imperative for moral action. He gives at least three formulations of the Categorical Imperative.

1."Act only according to that maxim by which you can at the same time will that it should become a universal law." (Ibid., 422)
2."Act as though the maxim of your action were by your will to become a universal law of nature." (Ibid)
3.Act so that you treat humanity, whether in your own person or in that of another, always as an end and never as a means only." (Ibid., 429)

What are Kant's arguments for the Categorical Imperative? First, consider an example. Consider the person who needs to borrow money and is considering making a false promise to pay it back. The maxim that could be invoked is, "when I need of money, borrow it, promising to repay it, even though I do not intend to." But when we apply the universality test to this maxim it becomes clear that if everyone were to act in this fashion, the institution of promising itself would be undermined. The borrower makes a promise, willing that there be no such thing as promises. Thus such an action fails the universality test.

The argument for the first formulation of the categorical imperative can be thought of this way. We have seen that in order to be good, we must remove inclination and the consideration of any particular goal from our motivation to act. The act cannot be good if it arises from subjective impulse. Nor can it be good because it seeks after some particular goal which might not attain the good we seek or could come about through happenstance. We must abstract away from all hoped for effects. If we remove all subjectivity and particularity from motivation we are only left with will to universality. The question "what rule determines what I ought to do in this situation?" becomes "what rule ought to universally guide action?" What we must do in any situation of moral choice is act according to a maxim that we would will everyone to act according to.

The second version of the Categorical Imperative invokes Kant's conception of nature and draws on the first Critique. In the earlier discussion of nature, we saw that the mind necessarily structures nature. And reason, in its seeking of ever higher grounds of explanation, strives to achieve unified knowledge of nature. A guide for us in moral matters is to think of what would not be possible to will universally. Maxims that fail the test of the categorical imperative generate a contradiction. Laws of nature cannot be contradictory. So if a maxim cannot be willed to be a law of nature, it is not moral.
The third version of the categorical imperative ties Kant's whole moral theory together. Insofar as they possess a rational will, people are set off in the natural order of things. They are not merely subject to the forces that act upon them; they are not merely means to ends. They are ends in themselves. All means to an end have a merely conditional worth because they are valuable only for achieving something else. The possessor of a rational will, however, is the only thing with unconditional worth. The possession of rationality puts all beings on the same footing, "every other rational being thinks of his existence by means of the same rational ground which holds also for myself; thus it is at the same time an objective principle from which, as a supreme practical ground, it must be possible to derive all laws of the will." (Ibid., 429)

Kant's Criticisms of Utilitarianism
Kant's criticisms of utilitarianism have become famous enough to warrant some separate discussion. Utilitarian moral theories evaluate the moral worth of action on the basis of happiness that is produced by an action. Whatever produces the most happiness in the most people is the moral course of action. Kant has an insightful objection to moral evaluations of this sort. The essence of the objection is that utilitarian theories actually devalue the individuals it is supposed to benefit. If we allow utilitarian calculations to motivate our actions, we are allowing the valuation of one person's welfare and interests in terms of what good they can be used for. It would be possible, for instance, to justify sacrificing one individual for the benefits of others if the utilitarian calculations promise more benefit. Doing so would be the worst example of treating someone utterly as a means and not as an end in themselves.

Another way to consider his objection is to note that utilitarian theories are driven by the merely contingent inclination in humans for pleasure and happiness, not by the universal moral law dictated by reason. To act in pursuit of happiness is arbitrary and subjective, and is no more moral than acting on the basis of greed, or selfishness. All three emanate from subjective, non-rational grounds. The danger of utilitarianism lies in its embracing of baser instincts, while rejecting the indispensable role of reason and freedom in our actions.

C. Königsberg Confidential: Book Review
by Simon Blackburn

Kant: A Biography
by Manfred Kuehn
(Cambridge University Press)
There is a scene in the film Superman III in which Lorelei Ambrosia, the blonde bombshell, is secretly reading the Critique of Pure Reason. "But how can he say that pure categories have no objective meaning in transcendental logic? What about synthetic unity?" she squeaks, before hurriedly hiding the book and picking up a trashy magazine as her gangster boss enters. The director's choice of book was perfect: no other single work could be so improbable, and so easily recognizable as such by the audience. You might just take Bertrand Russell on a beach holiday, as I once did; but Kant, never. (Incidentally, although she has not quite mastered the jargon, Lorelei's question is a good one.)

Kant is notorious not only for opacity and difficulty, but also for having lived about the most unpromising life imaginable for a biographer. He spent it entirely within a few miles of the desolate coastal town of Königsberg, or Kaliningrad, in northeast Prussia. He never travelled. In all his life he never saw a mountain and never heard a decent orchestra. He never married. Once he met a "beautiful and well brought up widow from somewhere else," but by the time he had calculated income and expenses, she had married someone else. Another girl, from Westphalia, also struck his fancy, but he was still thinking about making an offer when she crossed the border out of Prussia. Kant almost certainly never had any sexual relations, and one hopes for his own peace of mind that this was so, since he held that sex outside marriage dishonors human nature, and "exposes mankind to the danger of equality with the beasts."

Kant's life, like that of a monk, was regular to the point of caricature. The familiar story that the townspeople could set their clocks by the time at which he took his afternoon walk had at least some truth in it. The University of Königsberg was his monastery. There were no heroics: when, in 1794, he fell afoul of the theological censors appointed by the Rosicrucian bigot Frederick William II, he gave in and promised not to do it again. He lectured, wrote, declined, and died a safe university man.

Not only are the externals unpromising, but they seem perfectly to express the inner man. Kant was small, and self-controlled, and unhealthy. He was preoccupied with the state of his bowels, and he seems to have devoted a lot of quite public attention to what Hamann called his "evacuations a posteriori." He found it difficult to laugh. The Prussian virtues of discipline, efficiency, thrift, hard work, and obedience are all canonized in his life and in his writings. Surprisingly, it seems to have been not a Prussian but an Englishman, a man called Green, who led the young Kant into these rigorous pathways. It was Green, a merchant and a close friend, who impressed Kant with the virtues of living according to uncompromising rules or maxims, and before Kant it was Green by whose doings the townspeople set their clocks.

Yet in this exhaustive and fascinating biography, the distinguished German scholar Manfred Kuehn struggles to convince us that the bloodless, legalistic Kant is mainly a myth. For Kuehn, neither Kant nor his frontier town is half as bleak as the conventional picture has portrayed them. Königsberg, after all, was the first capital of Prussia, where Frederick the Great's grandfather had proclaimed himself king in 1701. (Prussia's third centenary is a matter of somewhat controversial celebration in Germany this year.) It was a proud cosmopolitan city in which Russian and English businessmen rubbed shoulders with Prussian academics and nobles.

Kuehn introduces us to a long list of more or less forgotten academics and divines, merchants and minor landowners, whose lives revolved around the university. In his account, Kant was in the thick of a rich social and intellectual life. Anthony Quinton once wrote that the trouble with Kant is that "he is a wild and intellectually irresponsible arguer. Any innate leaning that way must have been enhanced by the intellectual isolation of Königsberg, which preserved him from serious criticism." But Kuehn will have none of this, and the long list of Kant's academic wrangles certainly rebuts the charge that he was insulated from serious criticism.

Not only was Königsberg a kind of Athens of the Baltic, but this Kant, too, is hardly the cold automaton of legend. In his youth he played billiards well enough to be something of a hustler; and when targets refused to play with him, he turned to cards as a supplementary source of income. With his increasing respectability these adventures had to cease, but Kant was not immune to temptation, even after he had adopted one of his own iron-clad rules or maxims of conduct. So, emulating Green, he gave himself the rule of just one pipe of tobacco a day, but friends noticed that as the years went by the pipe got bigger. He seems to have been an enthusiastic guest and host, seldom dining alone, prone to talk about gossip and politics rather than matters intellectual, and not at all averse to a moderate quantity of wine.

Inevitably, for someone of a dour Pietist background, all this rioting gave rise to some serious soul-searching. In the early Lectures on Ethics gluttony comes in for special criticism--bestial, again; and in the more humanistic late work The Metaphysics of Morals Kant still tells us that stuffing oneself with food incapacitates a person "for actions that would require him to use his powers with skill and determination." It is obvious that putting oneself in such a state violates one's duty to oneself. Fortunately all is not quite lost:

Although a banquet is a formal invitation to excess in both food and drink, there is still something in it that aims at a moral end, beyond mere physical well-being: it brings a number of people together for a long time to converse with one another. And yet the very number of guests (if, as Chesterfield says, it exceeds the number of the muses) allows for only a little conversation ... and so the arrangement is at variance with that end, while the banquet remains a temptation to something immoral....How far does one's moral authorization to accept these invitations to intemperance extend?

With such a question buzzing in his mind, one would hardly expect Kant to have been the life of the party. Yet "jest, wit and caprice were in his command," raves (the verb is Kuehn's) the younger Johann Gottfried Herder, hastening to add, "but always at the right time, so that everyone laughed," slightly spoiling the effect. Kant apparently thought very highly of Fielding's romp Tom Jones. One cannot imagine that he thought as highly of Joseph Andrews, whose Parson Adams illustrates Fielding's unswerving devotion to simple good nature, contrasted with the cold qualities of rectitude and "abstract contemplation on the beauty of virtue."

Kant would have remained a fairly minor figure in the history of philosophy had it not been for one decade of thought and one decade of publication. In 1770, upon becoming professor of logic and metaphysics, he delivered his Inaugural Dissertation, On the Form and Principles of the Sensible World. Here, for the first time, some famous doctrines of the "critical philosophy" come into view. Kant insists on a number of sharp divisions. He separates concepts and intuitions, or intellect and sensation. He separates "things in themselves" from "things as they are for us," or, in other words, he distinguishes the noumenal from the phenomenal. He sees space and time as the forms of our sensibility, imposed on the noumenal world as a condition of our experience of it. But he also leaves room for a genuine "metaphysics," or science of the world as it is in itself, knowable through the pure principles of the understanding.

There was a fatal flaw lurking in all of this. The key to metaphysics would need to be causation: it is because the noumenal causes the world as we apprehend it that it is a possible object of knowledge. Thirty years previously, however, Hume had already blocked the road to any purely rational knowledge of what causes what. In Prussia, Hertz and Hamann soon brought Hume's criticism of speculative reasoning about causation to Kant's attention: it now seemed that causation itself had to be seen as the work of the mind, or as a form of sensibility. Kant was later to say that it was Hume who "first interrupted my dogmatic slumbers." It took a decade for him to come to terms with the problem that Hume had left him.

The result was the eight hundred and fifty-six pages of the Critique of Pure Reason, published in 1781, when Kant was fifty-seven years old. The central doctrine of this extraordinary work is the interdependence of intellectual cognition and experience: "Thoughts without content are empty, intuitions without concepts are blind." It takes both conceptual ability and its application in experience to generate intelligible thought. It follows that the pure metaphysics that Kant had previously imagined, his reasoning beyond the limits of experience, could have been nothing but an illusion.

To be sure, armchair or a priori reasoning is possible--but not about the world as it is in itself. Such reasoning concerns only the world as it appears to us. When we attempt to reason beyond this, wanting to know about the nature of the soul, or the world as a whole, or the existence of God, reason falls into contradiction, and its exercise is doomed to failure. As its name implies, the Critique of Pure Reason is fundamentally a skeptical work, and this is how it was seen by its contemporaries. Kant became famous as the Alleszermalmer, or all-crushing skeptic and critic of rational theology and metaphysics. Indeed, contemporary opinion tended to assimilate Kant not only to Hume, but even to the notorious idealist Berkeley--a charge with some justice to it, but one that particularly outraged Kant himself.

In the contemporary world, as Kuehn observes, Kant is more commonly seen as an opponent of skepticism, more interested in the scope of our knowledge than in its limits. Such are the revolutions of philosophical interpretation. This positive side is certainly there, but it is only part of the picture, since for Kant himself the point of the critical philosophy lay elsewhere entirely. It lay in its religious and moral implications. Throughout the 1780s, Kant wrote the works on moral and religious themes that stand alongside the Critique as his great legacy to philosophy. Groundwork of the Metaphysics of Morals appeared in 1784; and by 1790 there were two more critiques, as well as one book expounding his system in a more accessible form (Prolegomena to Any Future Metaphysics) and the strange Metaphysical Foundations of Natural Science, which sought to place Newtonian physics on a pure, a priori footing.

Even if Kant's life was speckled with outbreaks of conviviality, it is difficult to say the same for his uncompromising, law-intoxicated moral philosophy. Kant's moral psychology is one in which duty is forever at war with blind and slavish inclination, which itself is always a species of self-love. Emotions and desires are the enemy. You score moral points only when duty wins over them, and just because it is duty. In most of Kant's moral writings, in fact, the less you care about other things and other people, the better.

Bliss, for Kant, is equated with complete independence from any inclinations or needs, including feelings of compassion and sympathy with others. But since as human beings we are unlucky enough not to have this freedom, we must be on the alert to slap our feelings down. We gain moral credit only when we do so. Hence Schiller's famous jibe: "I must try to hate my friends so that my doing them good, which now I gladly do, will acquire moral worth." Kant's ideal, more accurately, is that you should try to be apathetic about your friends, and about everything else. Only then does real freedom, or real "autonomy," hold sway. Kant would not have been a happy reader of books extolling emotional intelligence.

Nor is a life of duty a bed of roses. As all students of philosophy learn, the duty of truthfulness extends for Kant to telling the mad axman where your children are sleeping (if he asks, that is, and makes you answer). There is no room to wriggle. You cannot argue that the axman has no right to the truth. That just means that you do him no injustice by lying. But you still inflict a wrong upon humanity, and violate a sacred command of reason. In Kant's account of morality, it is quite easy to wrong humanity. Not only the bestialities of gluttony and misdirected sex, but also more principled stands such as rebellion against a government, wrong humanity, no matter how unjust, arbitrary, usurping, or plain evil the government may be. It can be so grim doing your duty that we are forced to postulate a life after death where happiness and righteousness get back into alignment. The critical philosophy completely destroys any project of rational theology, but then our needs are supposed to step in and fill the gap. We may not be permitted to lie, but we are permitted the wishful thinking of eschatology.

In spite of such unpromising doctrines, Kant is undoubtedly the most influential moral and political philosopher of modern times. At present he probably has more, and more crusading, defenders among professional moral and political philosophers than ever before. He is a foil to "utilitarianism," which is equated in many minds with a fearsome social engineering that puts the individual firmly at the service of the collective. Better still, he directs attention away from any very demanding educational needs. According to the Greek tradition, virtue is rare and requires the most careful cultivation and practice; and democracy requires virtuous citizens. For Kant, by contrast, people have the possibility of autonomy, or freedom, and above all they deserve respect, just like that. They do not have to work to earn respect. And however dim or dumb they may be, democratic republicanism is the right form of government.

Kuehn shows in detail how these views developed. Just as with the critical philosophy, there was a revolution in Kant's thinking. As well as having a taste for Henry Fielding, Kant grew up accepting the ethical views of Frances Hutcheson, the great eighteenth-century Scottish moral philosopher. Hutcheson, who coined the phrase "the greatest happiness of the greatest number," founded morality on a "moral sense" or sentiment of impartial benevolence toward humanity. Kant was apparently disabused of this approach by reading Rousseau. He tells us about it:

I am an inquirer by inclination. I feel a consuming thirst for knowledge, the unrest which goes with the desire to progress in it, and satisfaction at every advance in it. There was a time when I believed this constituted the honor of humanity, and I despised the people, who know nothing. Rousseau set me right about this. This binding prejudice disappeared. I learned to honor humanity, and I would find myself more useless than the common laborer if I did not believe that this attitude of mine can give worth to all others in establishing the rights of humanity.

The trouble with benevolence, Kant came to feel, is that it appeals to our feelings. But Kant wants a moral order in which we do not just happen to concern ourselves for others. We are under a duty to each other: our equal dignity demands their respect, and "what properly belongs to me must not be accorded me as something I beg for." The problem with private benevolence, as with public charity, is that it treats its objects as pitiable, as beggars, and this is a way of refusing to recognize their rights. It conceals our own injustice. The beggar is to be submissive and grateful; the benefactor is to be gracious and generous. But a person with rights should not have to be either submissive or grateful; and the person who heeds those rights is doing no more than listen to a demand, and so listening is neither gracious nor generous. It is a matter of obligation.

There is something sublime here, and something that will appeal to anyone looking to legitimate a liberal order. The claim is that there is indeed such a thing as a rational way of living, and that there is a duty to respect it and to aim for it.

This duty is not something that we create, or happen to find burdening us, like a chore imposed on us either by our own will or by that of someone else. It is, rather, rationally mandated; reason makes it compulsory. Its authority is visible to any rational agent. And, unlike our inclinations, it is categorical and inescapable. Maxims of behavior that appeal to our well-being ("honesty is the best policy") merely advise us, but the law of morality commands us.

Thus Kant promises to provide the template or the form for a universal, liberal, Enlightenment politics. If the system works, there are no problems of skepticism, nihilism, or relativism. If our principles measure up, we need not fear that our favorite view is arbitrary or parochial, or that we are imposing our opinions without rational warrant on others over whom we have power. No wonder, then, that moral and political philosophers want the system to work. In this construction of the place of philosophy in the human world, philosophers are not mere bourgeois, selfish, and timid creatures of a particular time and place, vainly hoping to impose their liberal standards on others unlike themselves. They are in the vanguard, articulating the demands that, because of the very structure of reason itself, must be heard by everyone.

It may be that Kant, because of his pietistic Protestant background, got those demands slightly wrong. But that leaves the hope of being able to soft-pedal some of his absolutism while retaining the essence of his approach. This involves crying up the passages in which Kant seems a little less severe than usual. It means a little bit of pick 'n' mix, trying to tow Königsberg some way to Edinburgh, or to Athens. This is a major industry in philosophy departments from Cambridge to Los Angeles. There are Aristotelian Kants, and Humean Kants, and even postwar Parisian existentialist Kants. One surprising feature of Kuehn's book in this context is that while Kant himself is painted as a bit of a lad, the late Metaphysics of Morals, which is the main resource of humanizing movements, is put down as disappointing: "it reads just like the compilation of old lecture notes that it is."
Contemporary manifestations of Kantianism tend to work through ideas of what reasonable people could demand of each other, of "contractarian" and "procedural" approaches to the foundations of society and morality. The fountainhead, of course, was John Rawls's A Theory of Justice, and Rawls's Harvard has been the main powerhouse of the "back to Kant" movement in liberal political philosophy. But in truth there is a serious question about how far the Kantian trappings of Rawls's works, and those of his followers, are not necessary to the argument, and therefore dispensable.
A Theory of Justice cracks up a social and fiscal order somewhat resembling the social democracies of Western Europe, with their substantial freedoms and their substantial welfare floors. The book gives the impression that this is a Kantian exercise of pure practical reason, describing the necessary goal of rational politics. But over the years this appearance has eroded. Perhaps a nice liberal welfare state is no more (or less) than the kind of place in which some of us would choose to live. It appeals to us not because of our autonomy, or because of our especially clear gaze into the crystal ball of pure practical reason, but only because we are prudent, and mildly benevolent, and not obsessive about the powers of the state or the beauties of the market.

Even if we do not all want to go back to Kant, none of us can escape him. He invented the guiding metaphor of contemporary thought, of all thought since his time. This is his Copernican revolution: that the world as we know it is at least partly a creation of the conceptual and linguistic resources that we bring to it. He articulated the guiding principles of liberal political thought. He may never have seen a decent painting, but he wrote the most interesting work on aesthetics in Western philosophy after Aristotle. Russell thought that Leibniz was the greatest example of pure intellect that the world had ever known. Russell, who could write well, was naturally prejudiced against Kant, who could not write well; but surely Kant is the only other contender for the Western mind's laurels.

SIMON BLACKBURN is professor of philosophy at the University of Cambridge.


D.Immanuel Kant (1724-1804)

A series of brilliant notes

by Kelley L. Ross, Ph.D

Kant's most original contribution to philosophy is his "Copernican Revolution," that, as he puts it, it is the representation that makes the object possible rather than the object that makes the representation possible. This introduced the human mind as an active originator of experience rather than just a passive recipient of perception. Something like this now seems obvious:  the mind could be a tabula rasa, a "blank tablet," no more than a bathtub full of silicon chips could be a digital computer. Perceptual input must be processed, i.e. recognized, or it would just be noise -- "less even than a dream" or "nothing to us," as Kant alternatively puts it.

But if the mind actively generates perception, this raises the question whether the result has anything to do with the world, or if so, how much. The answer to the question, unusual, ambiguous, or confusing as it would be, made for endless trouble both in Kant's thought and for a posterity trying to figure him out. To the extent that knowledge depends on the structure of the mind and not on the world, knowledge would have no connection to the world and is not even true representation, just a solipsistic or intersubjective fantasy. Kantianism seems threatened with "psychologism," the doctrine that what we know is our own psychology, not external things. Kant did say, consistent with psychologism, that basically we don't know about "things-in-themselves," objects as they exist apart from perception. But at the same time Kant thought he was vindicating both a scientific realism, where science really knows the world, and a moral realism, where there is objective moral obligation, for both of which a connection to external or objective existence is essential. And there were also terribly important features of things-in-themselves that we do have some notion about and that are of fundamental importance to human life, not just morality but what he called the three "Ideas" of reason:  God, freedom, and immortality. Kant always believed that the rational structure of the mind reflected the rational structure of the world, even of things-in-themselves -- that the "operating system" of the processor, by modern analogy, matched the operating system of reality. But Kant had no real argument for this -- the "Ideas" of reason just become "postulates" of morality -- and his system leaves it as something unprovable. The paradoxes of Kant's efforts to reconcile his conflicting approaches and requirements made it very difficult for most later philosophers to take the overall system seriously.

Nevertheless, Kant's theory does all sorts of things that seem appropriate for a non-reductionistic philosophical system and that later philosophy has had trouble doing at all. Kant managed to provide, in phenomenal reality (phaenomena="appearances"), for a sphere for science that was distinct and separate from anything that would relate to morality or religion. The endless confusion and conflict that still results from people trying to figure out whether or how science and religion should fit together is deftly avoided by Kant, who can say, for instance, that God and divine creation cannot be part of any truly scientific theory because both involve "unconditioned" realities, while science can only deal with conditioned realities. In the world, everything affects everything else, but the traditional view, found even in Spinoza, is that God is free of any external causal influences. Similarly, Kant can be a phenomenal determinist with science yet simultaneously allow for free will, and that in a way that will not be entirely explicable to us -- a virtue when the very idea of a rational and purposive free will, and not just arbitrary choices, has involved obscurities that no one has been able to resolve. Kant's theory prevents psychological explanations for behavior, however illuminating, being used to excuse moral responsibility and accountability. Thus, the tragic childhood of the defendant, however touching and understandable, cannot excuse crimes commited in full knowledge of their significance.

Kant's approach is also of comparative interest because of the similar ancient Buddhist philosophical distinction between conditioned realities, which mostly means the world of experience, and unconditioned realities ("unconditioned dharmas"), which interestingly include, not only the sphere of salvation, Nirvana, but also space, which of course for Kant was a form imposed a priori on experience by the mind.

The problems that must be sorted out with Kant are at the same time formidable. Most important is the confusion that results from Kant mixing together two entirely different theories in the Critique of Pure Reason (1781). The first theory is that the fundamental activity of the mind, called "synthesis," is an activity of thought that applies certain concepts to a previously given perceptual datum from experience. It is upon this theory that the Critique of Pure Reason was planned with its fundamental division between the "Transcendental Aesthetic," about the conditions of perception (what Kant called empirical "intuition"), and the "Transcendental Logic," about the conditions of thought. Thus, Kant still says, as late as page 91 of the first edition ("A"), "But since intuition [Anschauung] stands in no need whatsoever of the functions of thought, appearances [Erscheinungen] would none the less present objects to our intuition" (A 90-91, Norman Kemp Smith translation, 1929, St. Martin's, 1965), without, that is, any need for mental synthesis.

However, right in the middle of his subsequent argument for why cerain concepts would be necessary and known a priori with respect to experience (the "Transcendental Deduction"), Kant realized that "synthesis" would have to produce, not just a structure of thought, but the entire structure of consciousness within which perception also occurs. Thus he says, "What is first given to us is appearance. When combined with consciousness [Bewußtsein], it is called perception [Wahrnehmung]" (A 119-120). It is the structure of consciousness, through synthesis, that turns "appearances" into objects and perceptions, without which they would be nothing. Consequently Kant made synthesis a function of imagination rather than thought, as a bridge between thought and perception, though this creates its own confusions (it still depends on the forms of thought and is still treated in the Logic). This move occurred because Kant hit upon the idea that synthesis produced the unity that we actually find in "apperception," i.e. in the unity of consciousness -- everything I know, think, see, feel, remember, etc. belongs to my consciousness in one temporal stream of experience. Synthesis therefore brings things into consciousness, making it possible for us to subsequently recognize that our consciousness exists and that there are things in it. Hume had described the result as "something betwixt unity and number," since it is paradoxically one thing and many things all at the same time.

These were all revolutionary ideas, exploring both the logical and the psychological principles on which the complex whole of consciousness could be generated, but they tore up Kant's original plan for his system so much that he was never quite comfortable with them. He then tried to paper over his most daring insights when he came to write both the Prolegomena to any Future Metaphysics (1783) and the changes that he introduced into the second edition of the Critique itself (1787, "B"). Thus Schopenhauer, who understood the meaning of Kant's change of approach, advised his readers that they would be wasting their time unless they obtained an edition of the Critique that included the whole text from the first edition. It is now standard to include both versions, with the original paginations in the margins.

The path to resolving the paradoxes of Kant's theory opens up with two basic realizations:  (1) Kant always believed that reason connected us directly to things-in-themselves, and (2) Kant's system is not a Cartesian theory of hidden, transcendent objects, but a version of empirical realism, that we are directly acquainted with real objects. Kant's notion that reason connects us directly to things-in-themselves does not allow for speculative metaphysics as practiced by the Rationalists because reason alone does not determine any positive content of knowledge ("Thoughts without content are empty; intuitions without concepts are blind," A 51). For that some datum is required. Kant allows that we possess two sources of input that can serve as such a datum, physical sensation and the sense of moral duty. Physical sensation precipitates an application of reason to experience, producing the perception of phenomenal objects. The supreme rational expression of this is science. The sense of moral duty precipitates an application of reason that generates ethics and religion. The supreme rational expression of this is the "Postulates of Practical Reason," the "Ideas" of God, freedom, and immortality which, to Kant, are required as conditions of the the Moral Law.

The differences between reality as seen in science and reality as seen in morality and religion reveal that there are aspects to existence that are not revealed by either datum alone. The two sources are also unequal in the magnitude and ultimate significance of their content. What science can investigate and know is apparently all but endless, but it still leaves us wondering, "What is it all for?" Morality and religion have a far more limited rational content, returning to many of the same issues over and over again, but such issues happen to include, not just the questions about how to live, but the ultimate questions about the meaning of life and existence ("Life, the Universe and Everything," in the memorable formula of Douglas Adams). That our moral datum does not lead to direct, positive knowledge of things that we are able to conceive, like God, leads Kant to characterize his system as transcendental idealism, that we have a subjective representation of such things, without the real intuition that we have of physical objects. The reality revealed by morality is thus for Kant a matter of faith (Glaube), an inference from the Moral Law which is itself present to us with an inexplicable authority. "Transcendental idealism" is thus profoundly different from other forms of "idealism," like the "subjective idealism" of Berkeley (what Kant called "empirical idealism") or the "objective idealism" of Hegel, both of which offer speculative certainties about the ultimate nature of things, which Kant does not do. The nature of things that we can know about concretely, for Kant, is revealed by science. Hence, Kantian transcendental idealism is equally attended by empirical realism.

How Kant can be certain that reason connects us directly to things-in-themselves is an question that he cannot answer. All that the Transcendental Deduction aimed at was showing that particular concepts, like causality or substance, are "necessary conditions for the possibility of experience." If successful, the Deduction limits the application of the concepts to experience, which is fine for Kant's philosophy of science, but doesn't help when he turns to morality and the "Postulates of Practical Reason." There his basic, but unjustified, theory of reason emerges. This shortcoming is what was directly addressed and answered by Jakob Fries, whose epistemology thus could save the generality of Kant's theory without falling back, like Hegel, into speculative metaphysics.
That Kant's theory is one of empirical realism is difficult to understand and easily forgotten. Since phenomena are undoubtedly mental contents, a point repeatedly stressed by Kant, it is natural and easy to infer from this a Cartesian "transcendental realism," according to which "real" objects, which are not mental contents, are things that we do not experience. A transcendental realism clearly contradicts Kant's transcendental idealism, but we can still be left thinking that what we really have is an empirical (subjective) idealism with a kind of transcendental agnosticism -- we don't know transcendent Cartesian objects, but they are the real objects (the Greek ontôs ónta, "beingly beings"). The lack of clear settlement in this area of basic ontology is the most intractable problem in Kant's philosophy.

The situation, however, is not unique to Kant. Something very similar can be found in Chinese T'ien-t'ai Buddhism (Japanese Tendai), as formulated by the great Chih-i (or Zhiyi, 538-597). There we find the doctrine of the "three truths" of "Emptiness" (neither existence nor non-existence nor both nor neither), "conventional existence," and "the Middle." "Emptiness" is rather like Kantian things-in-themselves where "dialectical illusion" is revealed by the Antinomies (a device similar to that employed by Nagârjuna, c.200 AD); "conventional existence" is empirical realism; and "the Middle" the Buddhist reconciliation of the two -- not a Hegelian "synthesis" because no absolute knowledge is produced to overcome the inconceivablility of Emptiness.

Such a religious doctrinal tradition, however, may not be considered by many to be very helpful with modern philosophical problems; and the T'ien-t'ai "Middle," however consistent with the paradoxes of Buddhist philosophy, is not a marked improvement over the balancing act in which Kant himself leaves us. The solution to the dilemma was grasped by Schopenhauer but not otherwise well understood by Kantians:  Consciousness does not just condition knowledge and perception, it conditions external reality. The modern context the most like this is in quantum mechanics, where, at least according to Niels Bohr, objects exist in a certain way, as discrete actualities, because they are observed. Otherwise, reality exists independently only as a sum of possiblities (where Schrödinger's Cat can be both dead and alive). This is not exactly what we get in Schopenhauer, who simplified matters by completely eliminating individuality from the thing-in-itself:  Individuality only occurs in space, the principium individuationis. That, however, also eliminated any possibility of individual immortality, which Kant thought was rather important. I do not think, indeed, that much progress has been made beyond that. Something new is required, as suggested in The Origin of Value in a Transcendent Function, "Ontological Undecidability," and "A New Kant-Friesian System of Metaphysics." If neither subject nor object, internal nor external, are ontologically fundamental, then we can stop worrying about in which place the real things really are, and the threat of either transcendental realism or empirical idealism disappears. This again sounds like what might be needed in quantum mechanics, and a Kantian quantum mechanics could offer hope both for the physics and metaphysics.

That brings us back to the datum of morality. Indeed, Kant's whole system does seem to come down to his own famous words, inscribed on his tomb, the "starry heavens above and the moral law within." If the existence of morality is as evident as the existence of physical objects, then Kant's dualism (empirical and transcendental) is required. If the existence of morality is not so evident, as with Nietzsche and currently fashionable nihilism, then there seems to be nothing left to motivate Kant's concern with transcendent objects.

But something that Kant overlooks is the Platonic overtone of his own famous statement. The "starry heavens" are especially striking, even for Kant, because they are beautiful. Most people see them, not as factual objects of science, but as things of awe, wonder, mystery, and beauty. Unfortunately, the mature Kant does not have the aesthetic realism of Plato and Schopenhauer, or of the younger Kant himself (in the Observations on the Feeling of the Beautiful and Sublime, 1764). To Plato, the beauty of things is a clue to the transcendent; but the mature Kant decided that only morality played that part. This only reinforces Kant's moralism and weakens his overall theory of value, let alone the metaphysics into which that fits.

The hope of fixing the loose ends of transcendental idealism, and of giving morality itself a credible realistic basis, lies back in the consideration of empirical realism. The unresolved paradox of a "realism" that was also a phenomenalism is the root of the greater difficulties considered above and below. If objects are immanent in experience but independent in their existence, then clearly there is a transcendent aspect to them, however that is construed. God, freedom, and immortality are not actually essential to that, and Schopenhauer did not believe in any of them; but Schopenhauer also overlooked Kant's analysis of "conditioned" versus "unconditioned" objects. Even a physical object, the universe, passes beyond experience and generates metaphysical paradoxes (the Antinomy of space and time), in so far as it is, in its entirety, an unconditioned whole. This is really just what Kant's Ideas are all about. All these matters in Kant's thought are therefore still open to clarification and development, as Fries and Schopenhauer attempted immediately, and as considered elsewhere in these pages.

Despite, but also because of, the paradoxes of his thought, much of philosophy in the Twentieth Century has been ill conceived knock-offs of Kant's theory. The idea that the mind produces the world it knows conspicuously turns up in Wittgenstein's theory of language and now with tedious, endless repetition in "post-modern" theories that see all reality as "socially constructed" on the basis of no more than "power" relationships (ultimately derived from the Marxist notion of ideological "superstructures" to class and economic relations). These all produce a fundamental paradox that was avoided by Kant, for they are all relativistic and subjectivist denials that knowledge even exists, which nevertheless maintain that this circumstance is a fact that can be known and demonstrated with some certainty -- though the "edifying" version of this recognizes the paradox by not trying such a demonstration, while still expecting us to accept the conclusion (!?). Thus, Wittgenstein sees all reality as created by particular languages, even though one might think this would imply that truths about language would be created by particular languages also. And since common sense expressed in most historical languages has actually affirmed that the world exists independently of what we say or think about it, this should mean that it does. Kant, of course, does not see the process of synthesis producing anything relativistic or subjectivist:  the realism of phenomena is fully meant. The knock-offs of Kant are rarely realistic.

While the knock-offs occupy fashionable opinion, basic misconceptions about Kantian theory are casually perpetuated. For instance, a defining characteristic of Kantian philosophy is that synthetic a priori propositions are not self-evident and can be denied without contradiction. What makes them true a priori is that they have a cognitive ground which is not in empirical intuition (i.e. perception). Although it is often claimed, as by the great French mathematician Poincaré, that the existence of non-Euclidean geometry refutes Kant's philosophy of geometry, in fact Kant's view of the nature of the axioms of geometry as synthetic a priori propositions means that Kant could have predicted the existence of non-Euclidean geometry. This should be obvious given any clear understanding of the meaning of "synthetic." Only Leonard Nelson fully appreciated this circumstance. The question of geometry in Kant is addressed in "The Ontology and Cosmology of Non-Euclidean Geometry."

A striking thing about Kant's life is how late he began his most significant work. He didn't complete his doctoral thesis and "habilitation," by which one qualified to teach in a German university, until 1755, when he was already 31 years old, having previously made a living as a tutor -- at such an age mathematicians and physicists are usually expected to have already burnt out. Kant's position, however, was still only a Privatdozent, which meant he was only paid by the student, and carried an academic teaching load that today would only be found in a community college. This difficult life only improved in 1770, when Kant finally was appointed to a regular chair of philosophy, at age 46. Nevertheless, Kant had already made a name for himself with his often original ideas in physics and astronomy and with his growing critique of the widely accepted, at least in Germany, thought of Leibniz (e.g. the seminal "The First Ground of the Distinction of Regions in Space," which upheld Newtonian arguments against Leibniz's denial of the existence of space).

The "Inaurgural Dissertation" that commemorated his appointment was the first real step towards the characteristic doctrines of the Critical Philosophy. Working that out, and writing the Critique of Pure Reason, still hampered by heavy teaching obligations, then took more than ten years. That book's publication in 1781 put Kant, at age 57, on the doorstep of a vast philosophical project, whose details he had already planned, but whose completion his age and health -- he was never a very robust man -- might well frustrate. His concern that he might actually die before finishing his work, in an age when sudden death was an all too familiar phenomenon, led him to concentrate his efforts with a discipline that has led to caricatures of him ever since -- his clock-like appearance for his daily constitutional, on what then became the "Philosopher's Walk" in Königsberg, is usually seen as evidence of habits mechanical to an absurd extent, rather than the caution and discipline of a frail and aging soul desperate to finish his life's work. His previous custom of dining out and enjoying conversation with his friends was sacrificed in the race against death. What his life had been like we learn from Ernst Cassirer:

"Thus," [F.T.] Rink says, "Kant in his early years spent almost every midday and evening outside his house in social activities, frequently taking part also in a card party and only getting home around midnight. If he was not busy at meals, he ate in the inn at a table sought out by a number of cultured people." Kant gave himself to this mode of life in such an easy and relaxed way that even the most meticulous psychological observer among his intimates was occasionally puzzled about him; in 1764 [Johann Georg] Hamann says that Kant carries in his head a host of greater and lesser works, which he however probably will never finish in the "whirl of social distraction" in which he is now tossed. [Kant's Life and Thought, translated by James Haden, Yale University Press, 1981, pp.51-52]

The race with death, happily, was won, and the key monuments of the Critical Philosophy, including the trilogy of Critiques, were produced. It was declining faculties that finally stilled his pen, before he actually passed away. Kant's grave has fortunately escaped the destruction that the Soviet occupation visited upon the sights of traditional Königsberg. Now that the city's Soviet name, Kaliningrad, awkwardly still commemorates the Stalinist President of the Soviet Union, but the Russians do not want to return the city to its German name, the proposal has been floated to actually name the city after Kant (i.e. Kantgrad). Since Kant's thought is truly the watershed of modern philosophy, and still the fruitful point of departure for the 21st century, no such monument could be more suggestive, encouraging, and hopeful.

I have enjoyed the good fortune to know a philosopher, who was my teacher. In the prime of life he had the happy cheerfulness of a youth, which, so I believe, accompanied him even in grey old age. His forehead, formed for thinking, was the seat of indestructible serenity and peace, the most thought-filled speech flowed from his lips, meriment and wit and humor were at his command, and his lecturing was discourse at its most entertaining. In precisely the spirit with which he examined Leibniz, Wolff, Baumgarten, and Hume and purused the natural laws of the physicists Kepler and Newton, he took up those works of Rousseau which were then appearing, Émile and Héloïse, just as he did every natural discovery known to him, evaluated them and always came back to unprejudiced knowledge of Nature and the moral worth of mankind. The history of nations and peoples, natural science, mathematics, and experience, were the sources from which he enlivened his lecture and converse; nothing worth knowing was indifferent to him; no cabal, no sect, no prejudice, no ambition for fame had the least seductiveness for him in comparison with furthering and elucidating truth. He encouraged and engagingly fostered thinking for oneself; despotism was foreign to his mind. This man, whom I name with the utmost thankfulness, and respect, was Immanuel Kant; his image stands before me to my delight. [Johann Gottfried Herder, Letters on the Advacement of Humanity, letter 79, quoted by Cassirer, op cit., p. 84]

Immanuel Kant (1724-1804), Note

Before his Critical period, Kant nevertheless had made a bit of a name for himself. Part of this was due to the Observations on the Feeling of the Beautiful and Sublime (1764), which shows a very different kind of Kant, as thinker and writer, than what becomes familiar in the later works. Indeed, Kant's moral observations in his four humour typology seem more sensible, realistic, and humane than the rigor of the Categorical Imperative.

Kant's most striking early contribution to knowledge, however, was his General Natural History and Theory of the Heavens (1755). Kant had two noteworthy theories in physics and astronomy. One was the "Nebular Hypothesis" of planetary formation. Kant reasoned that diffuse nebulae, dim clouds of dust and gas that were only first being well observed in his lifetime, would collapse under the force of gravity. As they did, they could begin spinning and would then spin out into a disk. From these spinning disks stars and planets would form. Unlike the greatest of earlier German philosophers, Leibniz, Kant was not himself much of a mathematician, so the theory was not given a mathematical form until the great French mathematician Laplace (1749-1827) in 1796. Although there was still argument in my childhood about the formation of planets, it now seems to be generally accepted that both stars and planets condense out of nebulae and collapsed, spinning disks of dust and gas. Kant was right. Unfortunately, some astronomy textbooks refer to the Nebular Hypothesis as the theory of Laplace alone, instead of the Kant-Laplace theory, and do not give Kant proper credit.

Kant's second theory was also about nebulae, of a different kind. Along with bright and dark diffuse nebulae and planetary nebulae (which have nothing to do with planets), there are spiral nebulae. Laplace believe that these were actually the spinning disks of the Nebular Hypothesis. Kant had a different idea. In 1750 Thomas Wright had suggested that the Milky Way, the Galaxy, was a vast spinning disk itself, consisting of stars and everything else, and that the earth was part of this system. An observational confirmation of this came from the great astronomer William Herschel in 1785. Kant's idea was that the tiny spiral nebulae were themselves external galaxies, "island universes" independent of the Milky Way. There was really no evidence for this. It was just a guess, and Kant may even have been confused about some issues. Nevertheless, it launched a great debate that lasted all the way until 1924. Astronomers were either Laplaceans or Kantians. The matter was settled by Edwin Hubble (1889-1953), using the recently completed Mount Wilson 100 inch telescope, in the San Gabriel Mountains above Pasadena, California (the mirror was hauled up the mountain by mules) -- visible from the San Fernando Valley. Hubble was able to identify Cepheid variable stars in nearby spiral nebulae. With this kind of variable stars, their period of variation is proportional to their absolute brightness. With their absolute brightness, compared to the apparent brightness, Hubble would know their absolute distance. They were far, far further away than the stars of the Milky Way Galaxy. They were in external galaxies. Kant was right. Now, since it was just a guess, how much credit can we give to Kant? A fair amount, since many great ideas in science begin as guesses. More importantly, if we ask who the first person was to conceive the form of the universe as we now see it, filled with "billions and billions" of galaxies (as Carl Sagan liked to say), the answer is just:  Immanuel Kant, a man who never left East Prussia and who never saw a mountain.

Speaking of East Prussia. Kant was born, lived, and died in Königsberg. This was a city founded in 1255 by the Teutonic Knights, but named after a crusading companion, King Ottokar II of Bohemia. Today, the names Prussia and Königsberg have both disappeared. After World War II, East Prussia was partitioned between Poland and the Soviet Union, with the northern half held as a part of metropolitan Russia itself. Most native Germans were expelled, and the German name of the capital was replaced with Kaliningrad, commemorating the President of the Soviet Union. With the fall of the Soviet Union, the "Kaliningrad Oblast" became a detached outliner of the Russian Republic, surrounded by Lithuania and Poland. Most Soviet era cities, like Stalingrad and Leningrad, have reverted to their pre-Communist names. But Kaliningrad has not, since a German name might imply that the district should be returned to Germany. It has been suggested that the city could named after Kant (Kantgrad), since he is buried there. But Kant, of course, was German himself. However, the city was not named after a German, but after the Slavic King of Bohemia. Königsberg thus could simply be translated, without any German overtones. It would be Korolyagora -- -- in Russian, the "King's Mountain" again.

Analytic and Synthetic:  Kant and the Problem of First Principles

Except for outright Skeptics, Aristotle's solution to the Problem of First Principles, that such propositions are known to be true because they are self-evident, endured well into Modern Philosophy. Then, when all the Rationalists, like Descartes, Spinoza, and Leibniz, appealed to self-evidence and all came up with radically different theories, it should have become clear that this was not a good enough procedure to adjudicate the conflicting claims. This awkward situation was then blown apart by Hume, under whose skeptical examination, reviving the critique of al-Ghazâlî, even the principle of causality crumbled.

Kant does not directly pose the Problem of First Priniciples, and the form of his approach tends to obscure it. Thus, the "Transcendental Logic" in the Critique of Pure Reason is divided into the "Transcendental Analytic" and the "Transcendental Dialectic." The "Dialectic" is concerned with the fallacies produced when metaphysics is extended beyond possible experience. The "Analytic," about secure metaphysics, is divided into the "Analytic of Concepts" and the "Analytic of Principles." "Principles" would be Principia in Latin, i.e. "beginnings," "first things," "first principles," where now in English, thanks to the drift in the meaning of "principle," the term must be reduplicated with an etymologically redundant "first." Kant, however, is here writing in German, and in place of Principia we have Grundsätze (singular Grundsatz, "principle," "axiom" -- literally "ground sentence"). The examination of the Grundsätze, however, is deferred until after and "Analytic of Concepts." Thus, were the Problem of First Principles to be raised, it seems like that would come after an examination of concepts. Since it is not raised at all, one is left with the impression that it has somehow, along the way, actually already been dealt with. It has.

The peculiarity of Kant's approach, from an Aristotelian (or Friesian) point of view, is not idiosyncratic. Kant approaches the matter as he does because he is responding to Hume, and one of Hume's initial challenges is about the origin of "ideas." While the Problem of First Principles is about the justification of propositions, Hume's Empiricist approach goes back to asking about the legitimacy of the very concepts, of which the propositions are constituted, in the first place. The Rationalists never worried too much about that. For Descartes, any notion that could be conceived "clearly and distinctly" could be used without hesitation or doubt, a procedure familiar and unobjectionable in mathematics. It was the Empiricists who started demanding certificates of authenticity, since they wanted to trace all knowledge back to experience. Locke was not aware, so much as Berkeley and Hume, that not everything familiar from traditional philosophy (or even mathematics) was going to be so traceable; and Berkeley's pious rejection of "material substance" lit a skeptical fuse whose detonation would shake much of subsequent philosophy through Hume, thanks in great measure to Kant's appreciation of the importance of the issue.

Thus, Kant begins, like Hume, asking about the legitimacy of concepts. However, the traditional Problem has already insensibly been brought up; for in his critique of the concept of cause and effect, Hume did question the principle of causality, a proposition, and the way in which he expressed the defect of such a principle uncovered a point to Kant, which he dealt with back in the Introduction to the Critique, not in the "Transcendental Logic" at all. Hume had decided that the lack of certainty for cause and effect was because of the nature of the relationship of the two events, or of the subject and the predicate, in a proposition. In An Enquiry Concerning Human Understanding, Hume made a distinction about how subject and predicate could be related:

All the objects of human reason or enquiry may naturally be divided into two kinds, to wit, Relations of Ideas, and Matters of Fact. Of the first kind are the sciences of Geometry, Algebra, and Arithmetic; and in short, every affirmation which is either intuitively or demonstratively certain [note: these are Locke's categories]. That the square of the hypothenuse is equal to the square of the two sides, is a proposition which expresses a relation between these figures. That three times five is equal to the half of thirty, expresses a relation between these numbers. Propositions of this kind are discoverable by the mere operation of thought, without dependence on what is anywhere existent in the universe. Though there never were a circle or triangle in nature, the truths demonstrated by Euclid would for ever retain their certainty and evidence.

Matters of fact, which are the second objects of human reason, are not ascertained in the same manner; nor is our evidence of their truth, however great, of a like nature with the foregoing. The contrary of every matter of fact is still possible; because it can never imply a contradiction, and is conceived by the mind with the same facility and distinctness, as if ever so conformable to reality. That the sun will not rise to-morrow is no less intelligible a proposition, and implies no more contradiction than the affirmation, that it will rise. We should in vain, therefore, attempt to demonstrate its falsehood. Were it demonstratively false, it would imply a contradiction, and could never be distinctly conceived by the mind. [Enquiries, Selby-Bigge edition, Oxford, 1902, 1972, pp.25-26]

Both paragraphs warrant quoting in full. The first now would seem properly more a matter of embarrassment than anything else. Whatever Hume expected from intuition or demonstration, it would be hard to find a mathematician today who would agree that "the truths demonstrated by Euclid would for ever retain their certainty and evidence." If Hume's fame rests on this point, there would be little to recommend it. The second paragraph, however, redeems the impression by giving us a logical criterion to distinguish between truths that are "relations of ideas" and those that are "matters of fact":  A matter of fact can be denied without contradiction.

This was the immediate inspiration to Kant, who can have asked himself how something "demonstratively false" would "imply a contradiction." A contradiction means something of the form "A and not-A." If a proposition expressing a matter of fact can be denied without contradiction, then the subject and the predicate of such a proposition cannot contain anything in common, otherwise the item would turn up posited in the subject but negated in the predicate of the denial. On the other hand, a proposition that cannot be denied without contradiction must contain something in the predicate that is already in the subject, so that the item does turn up posited in the subject but negated in the predicate of the denial. This struck Kant as important enough that, like Hume, he founded a whole critique on it, and also produced some more convenient and expressive terminology. Propositions true by "relations of ideas" are now analytic ("taking apart"), while propositions not so founded are synthetic ("putting together").

This clarified distinction Kant could then turn on Hume's own examples of "relations of ideas." Can geometry be denied without contradiction? Kant did not see that the predicates of the axioms of geometry contained any meaning already expressed in the subjects. They were synthetic. They could be denied without contradiction. Geometry would thus not have an intuitive self-evidence or demonstrative certainty that Hume claimed for it. Kant still thought that Euclid, indeed, would have certainty, but the ground of certainty would have to located elsewhere. Nevertheless, Kant is rarely credited, and Hume rarely faulted, for their views of the logic of the axioms of geometry. If the axioms of Euclid can be denied without contradiction, this means that systems of non-Euclidean geometry are logically possible and can be constructed without contradiction. But it is not uncommon to see the claim that Kant actually denied this, and it is Kant, not Hume, who is typically belaboured for implicitly prohibiting the development of non-Euclidean systems. This distortion can only come from confusion and bias, a confusion about the meaning of "synthetic" (even in Hume's corresponding category), and a bias that the Analytic tradition has for British Empiricism, by which the glaring falsehood of Hume's statements is ignored and Kant's true and significant discovery misrepresented. This curious and reprehensible turn is considered in detail elsewhere.

Kant, as it happens, also did not see how arithmetic could be analytic. In his own example of "7 + 5 = 12" (p. B-15), if "7 + 5" is understood as the subject, and "12" as the predicate, then the concept or meaning of "12" does not occur in the subject. This was rather harder to swallow than the point about geometry, for it seems rather "intuitively" certain that "7 + 5 = 12" cannot be denied without contradiction. Kant must have missed something. Hope for demonstrating the analytic nature of arithmetic came with the development of propositional logic, since a proposition like "P or not P" clearly cannot be denied without contradiction, but it is not in a subject-predicate form. Still, "P or not P" is still clearly about two identical things, the P's, and "7 + 5 = 12" is more complicated than this. But, if "7 + 5 = 12" could be derived directly from logic, without substantive axioms like in geometry, then its analytic nature would be certain. In their Principia Mathematica (1910-1913), Russell and Whitehead and, in the Tractatus, Wittgenstein thought that they could indeed derive arithmetic from logic. Their demonstrations, however, were flawed, and it turned out that substantive axioms were necessary, just like in geometry. The axioms are now those of axiomatic Set Theory, and it is Set Theory that concerns the foundations of arithmetic. Kant turned out to be right again, though, curiously, he is again rarely credited for this.

Kant's discovery, however, can be trivialized if it turns out that there are simply no analytic propositions at all. This task was undertaken by Willard Van Orman Quine ("Two Dogmas of Empiricism," 1950). The approach, simply enough, was Nominalistic. If we say that "red is a color" is an analytic proposition, where is "color" in "red"? I don't see it. If we say that the meaning "color" is in the meaning of "red," where are these "meaning" things? I don't see them. Thus, if language consists of words but not abstract meanings, then we don't have to worry about one meaning containing another. "Red is a color" is just a convention of our language, which is even what we can say about "P or not P." Besides the general failings of Nominalism, Quine's particular critique is well refuted by Jerrold Katz.

In Kant there is little left in the category of "analytic." Definitions and truths of logic are going to be about it; and the definitions themselves will be suspect when the concepts defined may or may not be legitimate. The meaning within a concept must also in some sense be "put together," and the ground of this will raise the same questions as the ground of synthetic propositions. Thus, Saul Kripke began to speak of "analytic a posteriori" propositions, when the meanings in the subject are themselves united on only a posteriori grounds, i.e. the basis of experience. Indeed, dictionary definitions of natural language words are prima facie of conventional usage, e.g. how a pot is different from a pan, and the meaning of any words can be simply stipulated for some appropriate purpose, e.g. a "designated hitter" can go to bat for some particular member of a baseball team (usually the pitcher), without otherwise replacing him in other play. Thus, a big fight over the existence of analytic propositions doesn't in the end make that much difference. Synthetic propositions are the key anyway, as they were if Kant wanted to answer Hume's critique of causality.

For, indeed, outside of an axiomatized logic itself, the First Principles of Demonstration will be synthetic. However Kant can explain the truth of non-empirical synthetic propositions, i.e. those that are a priori instead of a posteriori, that will be his answer to the Problem of First Principles. They are clearly now, after Hume, not going to be self-evident. Yet Hume himself is often poorly understood. While it is common to say that Hume denied the existence of synthetic a priori propositions, there is some question about whether he actually does. He says that the relationship of cause and effect is not discovered or known by any reasonings a priori, but that is not the same thing. A synthetic a priori proposition is not known from any reasonings. In fact, Hume does not see that the relationship of cause and effect is discovered or known from anything, since it is not justified by experience, in which there is no necessary connection between cause and effect, and there is in fact nothing in the cause to even suggest the effect, much less than the effect must follow. Hume's famous explanation was a psychological one, that we become accustomed to the association of certain events ("causes") with others ("effects"); but this, obviously, carries no weight whatsoever about the nature of things, which is what makes Hume, very properly, a Skeptic.

At the same time, Hume had no doubts whatsoever of the necessity of cause and effect. This is where he is commonly misrepresented. People assume that because he was a Skeptic, then he must have thought it possible for causes to occur without effects, i.e. for the principle of causality to be contradicted in actuality. He never had any such expectation, and in fact he ruled out a priori, not only miracles, but also chance and free will just because they would violate (a very deterministic) causality. Confusion over this occurs because people do not appreciate that Hume as an "Academic" Skeptic, holding that lack of knowledge (the meaning of "Skepticism") does not rule out "reasonable" beliefs. Causality is a "reasonable" belief because, as Hume says, "All reasonings concerning matter of fact seem to be founded on the relation of Cause and Effect" [Enquiry, op. cit., p. 26]. So without it, we would have no basis of reasoning in daily life. Thus, Hume says:
Nor need we fear that this philosophy, while it endeavors to limit our enquiries to common life, should ever undermine the reasonings of common life, and carry its doubts so far as to destroy all action, as well as speculation. Nature will always maintain her rights, and prevail in the end over any abstract reasoning whatsoever. Though we should conclude, for instance, as in the foregoing section, that, in all reasonings from experience, there is a step taken by the mind which is not supported by any argument or process of the understanding [i.e. from cause to effect]; there is no danger that these reasonings, on which almost all knowledge depends, will ever be affected by such a discovery. [ibid., p. 41]

Kant therefore understood that Hume's problem was not with the quid facti, that there were causes and effects, and necessary connection, but with the quid juris, the epistemic justification of the principle. While some philosophers spent much of the 20th Century congratulating Hume for having discovered that causality might not exist, they never seem to have noticed that he explicitly denied having done anything of the sort. Kant already knew the type, who "were ever taking for granted that which he doubted, and demonstrating with zeal and often with impudence that which he never thought of doubting..." [Prolegomena to Any Future Metaphysics, p. 259, Lewis White Beck translations, Bobbs-Merrill, 1950, p.6].

Kant's solution to the quid juris in the Critique of Pure Reason was the argument of the "Transcendental Deduction" (in the "Analytic of Concepts") that concepts like causality are "conditions of the possibility of experience," because they are the rules by which perception and experience are united into a single consciousness, through a mental activity called "synthesis." Once the existence of consciousness is conceded (which not everyone, e.g. behaviorists, might be willing to do), then whatever is necessary for the existence of consciousness must be conceded.
This is a strong argument and, decisive or not, is heuristically of great value, especially when we untangle it from the earlier views of perception in the Critique. However, it suffers from a couple of serious drawbacks. One is that, like Hume's own explanation, it is a psychological approach that does not necessarily tell us anything about objects, i.e. consciousness may be united in a way that is irrelevant to external things. Kant seemed to recognize this himself when he said that none of this gives us any knowledge of things-in-themselves. This problem was never properly sorted out by Kant, and is considered independently in "Ontological Undecidabilty".

The second drawback of Kant's argument is that it would only work, indeed, for the "conditions of the possibility of experience," and not for any other matters which might seem to involve synthetic a priori propositions. Hume himself was just as concerned about morality as about causality, and found himself in the same Skeptical position in both matters. The only comparable thing that Kant can do for morality, however, would be to employ a principle of the "conditions of the possibility of morality." But this would require conceding that morality exists, which is something that a very large number of people in the 20th century, far beyond behaviorists, would not be willing to do. Nor does it make one a Kantian merely to vaguely appeal to human "rationality" (e.g. John Rawls) as a basis for morality, since this really just begs the question of justification -- besides violating Hume's famous observation that propositions of obligation ("ought," imperatives) cannot be logically derived from propositions of fact ("is," indicatives).

Keeping in mind that First Principles cannot be proven, and that synthetic propositions can be denied without contradiction, the conspicious historical alternatives seem to be to deny one or the other. Hegel denied the first, by taking the equivalent of Kant's Transcendental Deduction as itself a part of metaphysics and a proof, by means of novel principles of "dialectical" logic, of moral and metaphysical truths. To an extent, Hegel may also have denied the second, as Leibniz certainly did, treating any moral or metaphysical truth as analytic, if only from the point of view of divine omniscience. Either such move, however, cannot escape the original embarrassments of Rationalism, or avoid the devastation inflicted by the criticisms made by Hume and Kant.
Less conspicous historically was Jakob Fries, who could accept the proper meanings of "First Principle" and of synthetic propositions. The Friesian theories of deduction and of non-intuitive immediate knowledge make it possible to preserve the advances of Hume and Kant without falling back into Rationalism or heading for the Nihilism (so different from Hume's Skepticism), relativism, scientism, pragmatism, etc., so conspicuous in the 20th century. Later, Karl Popper proposed a special solution for the Problem in that science, by using falsification, does not need to worry about a positive justification of First Principles at all. This enables scientific progress to heedlessly continue, as it has, regardless of the status of any philosophical solution.

Thus, Kant gave us the real elements of the solution of the Problem of First Principles, even though he could not complete and seal the matter himself. Indeed, no one can hope to do that, even as new elements and new understanding of the solution emerge over time.

Analytic and Synthetic:  Kant and the Problem of First Principles, Note

In his earlier writings, in Latin, Kant had actually used the Latin expression principia prima, "First Principles." In the Critique of Pure Reason, we get an explicit discussion of principia only at the beginning of the "Transcendental Dialectic":

The term 'principle' [Prinzips] is ambiguous, and commonly signifies any knowledge [Erkenntnis] which can be used as a principle [Prinzips], although in itself, and as regards its proper origin [Ursprung], it is no principle [Principium]. Every universal proposition, even one derived from experience, through induction [Induktion], can serve as major premise [Obersatz] in a syllogism; but it is not therefore itself a principle [Principium]. [Norman Kemp Smith translation, St Martin's Press, 1929, 1965, p.301, A 300]

Here the difference between Kant's use of the German term and the Latin is, shall we say, lost in translation -- an entirely unnecessary loss, since the Latin term could have been used in English just as in German. Kant explains the drift in meaning of "principle," but instead of contrasting principium with principium primum, as in English we can contrast "principle" with "first principle," he contrasts German Prinzips with Latin Principium. By translating both the German term and the Latin one as "principle," Kemp Smith obscures the difference between a principle, in the modern sense, and a first principle. This may reveal that Kemp Smith actually isn't very sensitive or interested in either first principles or the Problem of First Principles. Indeed, Anglo-American philosophy, with its empiricist tendencies, has not been attracted to anything so un-empirical as first principles.
The passage also displays a bit of evidence that Kant takes the derivation of universal propositions from experience through induction as unproblematic. He cannot have been unaware of the Problem of Induction, having read Hume, but had not worked out, as no one would until Karl Popper, that there is a solution.

Kant's Transcendental Idealism

The obscurity of Kant when it comes to his theory of empirical realism and transcendental idealism is largely due to his terminology and the difficulties of reconciling parts of his theory. Since "transcendental" is contrasted with "empirical," the two terms are epistemological and mean "independent of (i.e. transcending) experience" and "immanent in experience." Since "realism" is contrasted with "idealism," those two terms are ontological and mean "independent of my existence" and "dependent on my existence." Berkeley was for Kant the characteristic "idealist," and undoubtedly an empiricist, while Descartes was a "realist," believing commonsensically that objects exist independent of us, but who also thought that we could only know their essences through "clear and distinct" innate ideas, not experience. This made Descartes a "transcendental" realist.

If we try to construct a square of opposition using Kant's two distinctions, we have some trouble. A strictly constructed square of opposition would look like the one at right. "Transcendental" (e) is the negation of "empirical" (e), and "idealism" (r) is the negation of "realism" (r). The structure we get, however, does not work for Kant's theory. Transcendental idealism and empirical realism would be contradictories and so cannot both be true, as Kant requires. Similarly, transcendental realism and empirical idealism are also contradictories and so cannot both be false, as Kant requires. The features of the square of opposition that we would expect Kant's theory to conform to would be that "contraries," the two upper members, are both false, while the "subcontraries," the two lower members, are both true.

If we want such a square of opposition, it will have to be rearranged without regard for the strict logical properties of the terms. We can save the distinctions and do that by recalling that opposites contradict each other only when applied to the same objects. Black coal and white snow are not contradictions. Kantian realism and Kantian idealism are thus reconciled by a distiction, that between phenomena and things-in-themselves. The former applies to the former, and the latter to the latter.

We can then produce a square like the one at right, which allows for the traditional truth values. In this version the definition of "transcedental idealism" has actually been left out. Kant's position, although terminologically embracing the two lower members, is really well defined by only one of them, empirical realism. However, saying that the objects of knowledge are immanent in experience and independent of our existence involves a paradox. How can something be independent in existence and yet dependent or immanent in our experience, our representation?
...the representation alone must make the object possible... ...representation in itself does not produce its object in so far as existence is concerned... [A 92]

The common sense, direct acquaintance with objects, part of this is what Kant appears to mean by his empirical realism, while the paradoxical, "in me but not of me," metaphysics is what he means by "transcendental idealism." This is the paradox addressed by Schopenhauer and by "Ontological Undecidability."

However, using the strict definitions, "transcendental idealism" means something else, as reproduced in the entry at left. If "transcendental" means, epistemically, "independent of experience," but "idealism" means, ontologically, "dependent on subjective (my) existence," then "transcendental idealism" would have to mean knowledge of objects that are dependent on my existence but independent of my experience. This seems to be, not just a paradox, but an out and out contradiction, since if something exists as an epiphenomenon of myself, it hardly seems like it could be independent of my experience. Berkeley's principle was "to be is to be perceived," but this kind of "transcendental idealism" would require that something is because of my existence but then is not perceived. This might work on the basis of Spinoza's metaphysics, where my existence is God's existence, but God's knoweldge far transcends mine. Nevertheless, since anything is God, God is part of my experience after all.

What this peculiar meaning of "transcendental idealism" reveals are the loosest ends of Kant's thought. The terminology of "transcendental," "empirical," "realism," and "idealism" does not seem well ordered for Kant's purposes, in part because those purposes are unsettled. The contradiction of the strict rendering of "transcendental idealism" might be resolved if we say that there is simply no knowledge in this case, which is pretty much what Kant says about things-in-themselves -- the soul certainly depends on my existence but is not part of my experience because I don't have any knowledge of it. But then Kant doesn't want to go all the way with that. Morality doesn't fit into empirical reality, but then maybe that isn't too bad, since morality is really "regulative" rather than "constitutive" (of metaphysical entities). What is bad are "God, freedom, and immortality," which totally upset the applecart. If there are such things, they are about transcendent objects which, at least in one case, are independent of my existence. If they are only objects of "faith," we want to know how that is motivated; and if they are motivated as necessary conditions of the Moral Law, then it seems like they would be as much matters of knowledge as the necessary conditions of experience, i.e. causality, substance, etc.

My view is that the way out of this is through Friesian epistemology and "Ontological Undecidability." Nevertheless, Kant's theory, as an approximation, is superior to any that have come since -- let alone the dismal exercises in nihilism, scientism, and scholasticism that are now so popular.

Intuition and Mysticism in Kantian Philosophy

While Kant's term "intellectual intuition" is thrown around rather casually in post-Kantian philosophy, the usage rarely conforms to Kant's meaning. Kant contrasts "intellectual" with "sensible" intuition (Anschauung) on the basis of the active or passive role of the object. Thus, while objects are presented to a (passive) sensible intuition, objects are created by an (active) intellectual intuition. To Kant himself, this meant that only God would have an intellectual intuition. In the history of philosophy, the "active intellect" of Aristotle and Neoplatonism may be the antecedent of the idea of intellectual intuition, though this would tend to blur the difference between the self and God, since it looks like there is only one active intellect -- which was precisely the point for a system of mysticism like Neoplatonism.

Kant, of course, had no interest in mysticism, famously pillorying the Swedish spiritualist, Emanuel Swedenborg ("Dreams of a Visionary, Explained by Dreams of Metaphysics," 1766), but it is important to note what mysticism would be in Kantian philosophy. Any kind of mysticism is going to be a kind of immediate knowledge that is an intuitive understanding, i.e. the opposite of a discursive understanding, where an intuitive understanding is immediate and unarticulated, while a discursive understanding is mediate and articulated. There is going to be no intuitive understanding in Kantian philosophy -- i.e. no understanding that stands on its own as knowledge, an understanding that is a ground for substantive truths. An intuitive understanding which is not knowledge is the common and essential experience of insight which is ordinarily and non-technically called "intuition," e.g. "My intuition is that murder is wrong" (in German, Nelson called it Intuition in contrast to Kantian Anschauung). This kind of "intuition" is not evidentiary, i.e. it doesn't prove anything. In Socratic/Platonic terms, it is only opinion. It can only be justified when analyzed, reduced to discursive understanding, and grounded accordingly [note]. Were ordinary "intuitions" evidentiary, and so items of knowledge (Erkenntnisse, cognitions), then this would be "intuitionism," the theory that knowledge is grounded by such intuitions [note]. The self-evidence of Aristotelian first principles is a theory of this kind, with the proviso that intuitive self-evidence follows, rather than precedes, discursive understanding. Other forms of intuitionism may claim intuitive understanding prior to discursive, if the latter is considered even possible.

While mysticism is a form of intuitionism, not all intuitionism is mysticism. The difference, again, will be in the objects. Mysticism is intuitive knowledge of transcendent concrete objects, i.e. not the phenomenal or material concrete objects of ordinary perception. The mystic sees things that are not part of ordinary experience. In Kantian terms, transcendent objects cannot be understood because they cannot be consistently articulated. For Kant, a theory of transcendent objects ("dialectic") generates antinomies. If a Kantian theory allowed for mystical knowledge, it would have to be unanalyzable, unrenderable into a system of discursive understanding of transcendent objects. This is rather like what many mystics say, since they gain knowledge which is ineffable and inexpressible. On the other hand, mystics also claim to intuitively derive knowledge which is analyzable and expressible, although only intuitively justified, since, for instance, al-Ghazzali (1059-1111) finds specific justification of Islâm and its doctrines through mystical insight.
The intuitive apprehension of abstract objects does not rise to the level of mysticism, since abstract objects do not have independent existence -- except when substantialized in Platonism, a theory rarely followed since. Intuitions of abstract objects concern meaning, and in general the ordinary sense of "intuition" (Intuition) applies to this. Such intuitions, when analyzed, are the basis of analytic truths, but whether the meanings apply to existence is a separate question (pace St. Anslem and Descartes), which requires an evidentiary basis. The mystical claim would have to be that an intuitively apprehended abstract object is also intuitively known to apply to existence, in a way, analyzable (as in Anselm's "ontological argument") or unanalyzable, that transcends ordinary perception and experience.

An important distinction in mystical claims will be between objects which are independent and which are identical to the subject of mystical knowledge. This itself is an analyzable characteristic of mystical intuition. In monotheistic religions, God will tend to be seen as independent. This was not an open question, and the Christian mystic always ran the risk that contrary truths learned through mystical intuition might conflict with Orthodoxy -- but the Catholic Church never denied that such an avenue of knowledge existed, as with St. Teresa of Ávila (1515-1582). Other mystics, however, paid the price of their experiences at the stake. In Judaism and Islâm, with looser institutional authority over doctrine, the drift of claims towards extinction of self and identity with God is conspicious. Some efforts were made in Islâm to suppress this, like the execution of al-H.allâj (in 922), but the precedent was powerful. An artifact of this in Judaism remained with the philosopher Spinoza, whose sense of identity with God is crystal clear, but who cannot properly be considered a mystic, since his God is not transcendent, but immanent, identical with all the objects of perception, and who does not claim intuitive knowledge beyond the minimal Aristotelian claims about first principles. Nevertheless, Spinoza retains a strong mystical affect, the "intellectual love of God," which helps explain the meaning to him of a system that otherwise is rationalistic and seems devoid of religious appeal.

The distinction between independent and identical objects can be seen to overlap Kant's between intellectual and sensible intuition. Only a sensible intuition could relate one to an independent transcendent object, since such a thing clearly cannot be created by one's knowing it. However, if the mystic is identical to the transcendent object, this could allow for an intellectual intuition, depending on the metaphysics of the object. It is possible for God's existence to be presented to him passively, in which case he would have sensible knowledge of himself; or, God may actually create his own existence, like that of anything else, merely by knowing it. This fits Spinoza's priniciple of a substance, namely God (Spinoza's only substance), being self-caused. There, if the mystic is identical to God, who also creates everything else through intellectual intuition, all mystical knowledge will be of the nature of an intellectual intuition.

This is even simpler in Buddhism, where there are no substances and, at least in some forms of Buddhist philosophy (e.g. Yogacara), all things are clearly created by Mind. In Pure Land Buddhism, an important meditative practice is the visualization of the Pure Land of the Buddha Amitabha. It is always possible to interpret this as unrelated to the independent, or even real, existence of the Pure Land, but the metaphysics clearly allows that the Pure Land is actually created by the act of visualization, since all things are Mind dependent. This would be an intellectual intuition in a strong Kantian sense, and a form of mysticism, with the transcendence of the Pure Land, in which the identity with the mystical object is facilitated by the absence of any substantial independence of things whatsoever. Similarly, the Tibetan "Book of the Dead" urges the deceased to realize that the visions of the hereafter are not independent but created by their own Mind. Thus lies the path to Enlightenment and Salvation.

In light of this examination, we should revisit the charge of mysticism against Rudolf Otto. Since Otto does not claim intuitive knowledge of transcendent objects, he clearly is not a mystic. The natures of transcendent objects, to the extent that they can be theorized at all, are matters of rational Kant-Friesian metaphysics (after the fashion of Kant's "postulates of practical reason," which resolve some antinomies); and Kant-Friesian metaphysics tends to dismiss more substantive doctrine from historic religions (e.g. the Trinity, transsubstantiation, etc.). Otto's famous theory of "numinosity" is about a property, and so an abstraction, whose existence is certified by its presence in the objects of experience, but which in an important way is not a natural property, since it is invisible to science and is unrelated to mundane utility. The numinosity of God is natural to Otto, but his God comes from the Kantian Ideas, besides historic religions, and divine numinosity derives from no more than a phenomenology of such religions.

So is there mysticism? Of course, there actually are mystics, most of whom are clearly sincere and deeply moved or transformed by their experiences. But there is no philosophical mysticism in the sense that philosophy could, as the Neoplatonists believed, certify, verify, and theorize the results of mystical intuitions. Given a Kantian epistemology and metaphysics, no rational or intelligible system can be built from mystical intuitions, analyzable or unanalyzable. This, however, should be no more than what we would expect given the contradictory claims of mystical or dogmatic authorities in world religions. The antinomical choices between mystical intuitions as intellectual or sensible, of independent or identical objects, of a divine substance (personal or impersonal) or ultimate Emptiness, cannot be resolved on the evidence of mystical knowledge, since the knowledge of different mystics confirms each of these and, as Hume would say, the evidence of one tends to refute the evidence of the other. This in itself is one of the most important features of human existence, since it leaves us without any rational certainty that there are transcendent objects at all. The mystic may just be hallucinating (or lying), whether beholding the Virgin Mary or visualizing the Buddha Land. As considered elsewhere, however, this simply leaves us faced with the choices of the right and the good without any confidence in the ulterior considerations of reward and punishment. Behind our veil of ignorance, it is character and benevolence that are proven.

Intuition and Mysticism in Kantian Philosophy, Note 1

Problems of justification are covered elsewhere. In Kant's theory, complications arise over Kant's original, "architectonic," conception of intuition (Anschauung) because, as considered in the main essay on Kant, perception itself comes to be seen (in the

Transcendental Deduction) as a product of mental activity. If perception is itself active and intellectual, then the simple distinction between sensible and intellectual intuition, or even between intuition and thought, becomes confused. Friesians like Nelson don't deal with his very well and tend to take over Kant's own naive version of the theory.

However, as is examined in detail in The Origin of Value in a Transcendent Function ("Intuition and the Immanent Object), the immediacy of intuition that is lost when we consider perception to be the result of active mental synthesis returns when we realize that this synthesis is an activity that cannot occur in the conscious mind. Perception is spontaneously produced by a preconscious activity; and even if it is governed by Kant's "pure concepts of the understanding" as rules of synthesis, these concepts do not accompany the results as conceptual or semantic content. Perception can occur without being understood, without particular things being seen, or without a particular recognition determined by the percept -- as in the Gestalt tricks where different things (e.g. faces or candlesticks) can be seen in the same shapes. The difference between conceptual meaning and perceptual object must be maintained, even when the empiricist tabula rasa is rejected and mental processes are allowed into the formation of perception. It is thus possible to continue speaking of intuition pretty much as Kant and the Friesian do, even after taking into account the way that the Transcendental Deduction undermines Kant's original view of intuition. There is also the ontological aspect to this, that the phenomenal objects immanent in perception are undecidedly both real/external and subjective/internal.

Intuition and Mysticism in Kantian Philosophy, Note 2

 In arguments about mathematics and set theory, "intuitionism" tends to mean something else, which can be very confusing. Mathematical intuitionists don't like mathematical or logical constructions that cannot be visualized (hence, "intuited") and so tend to be wary or disapproving of infinities. Such scruples, however, which may be empiricist in origin, seem to have had little effect on the practice of mathematics and, if taken seriously, would make much of modern mathematics, including non-Euclidean geometry, suspect. While Kant might be said to be a kind of intuitionist in this sense, since he thinks that the axioms of geometry and arithmetic are grounded by visualization, there is nothing to prevent the logical extension of mathematics beyond our capacity for visualization, which in fact is what has occurred. While Kant's mathematics is somewhat intuitionistic in the modern mathematical sense, it is not necessarily intuitionistic in the traditional epistemic sense, since our mathematical "intuitions," e.g. "that looks like a triangle," can be wrong. The Kantian mathematical intuition is much more like perception, an empirical intuition, than it is like a true self-justifying, evidentiary intuition -- a Kantian mathematical intuition, like an empirical intuition, can be misunderstood, while the evidentiary intuition of (epistemic) intuitionism is itself a kind of infallible understanding. To prevent confusion, the mathematical sense of "intuition" and "intuitionism" is not used in the text.
The Critique of Pure Reason