Copyright 1996 by Tad Beckman, Harvey Mudd College
Immanuel Kant represents for us the spirit of the Enlightenment with which the 19th Century opened. He should be considered in
contrast to Sigmund Freud who represents the spirit of distress and alarm with which the 19th Century ended. In Kant we find a person
who trusted human reason optimistically and completely; in Freud we find one who doubted the internal "honesty" of reason and
constructed a well documented theory of the unconscious reasoning processes. Thus, from Kant to Freud, we witness the profound
changes of vision that Europeans (and Americans) experienced in the 19th Century.
Immanuel Kant was born in Koenigsberg, East Prussia, in 1724; he lived in the same city until his death, in 1804. Kant's parents were Pietists (a strongly evangelical, reformist sect of Protestantism) and, while Kant himself rejected the evangelical side, he remained a deeply religious person throughout his life. Kant's parents were simple, industrious people, and he lived a similar, methodical existence himself.
Kant attended the University of Koenigsberg, studying classics and theology, first, and then physics and philosophy. In 1755, he began a teaching career at the University, as a lecturer, and this lasted for the remainder of his active life. In 1770, he became Professor of Logic and Metaphysics. Kant became a popular teacher; indeed, he was the best-known professor in Germany by his later years.
Kant's first and most famous book was Critique of Pure Reason, published in 1781, when he was 57. It opened up so many new problems and ideas for him that he became a prolific writer, producing at least fifteen other books, within the next seventeen years. The very next book, indeed, was his Prolegomena to Any Future Metaphysics (1783) which intended to streamline and simplify the issues of the Critique .... Kant made it clear that this work was offered to those who had difficulty handling the "synthetic method" of the former work but went on, "should any reader find this sketch, which I publish as the Prolegomena . . ., still obscure, let him consider that not everyone is bound to study metaphysics . . . In such cases men should apply their talents to other subjects." (PAFM, Intro, 11)
One effect of Kant's thinking was clearly to cast doubts on the noumenal world and, hence, on any divine origin of ethical principles. Given his own faith, it was necessary to discover the origins of a moral life in human reason itself. And in 1785, he published the Foundations of the Metaphysics of Morals. This was followed, later, by Critique of Practical Reason (1788), Critique of Judgment (1790), and Religion within the Limits of Reason Alone (1793).
Kant's place in the history of Western philosophy certainly does not stem from the ease with which he can be read (neither then nor now). Nevertheless, that place is guaranteed by his brilliance. Europe had witnessed almost two centuries of rapid scientific innovation, beginning perhaps with Galileo's analysis of the motion of a pendulum, in 1608. Descartes, Locke, and others had attempted to create a new philosophical foundation (and, hence, understanding) of this "new science." Indeed, the whole modern period (Descartes through Kant) is a discussion of metaphysics and epistemology that attempts to place science on a firm foundation of human reason while maintaining a separate foundation for religious, social, and political thought. [NOTE: One might fairly ask WHY science had to be put on a new foundation. The answer lies in the way in which the "new science" was a radical revolution, departing from its old Scholastic (Aristotelian) foundations.] But that whole discussion had pretty much come to naught by the time of Kant. Two broad positions had been identified and articulated. Empiricism anchored everything that we can know in sense experience but was unable to account thereby for general knowledge or principles of judgment. In particular, Empiricism fell short of demonstrating how universal and causal scientific knowledge is possible. Rationalism, on the other hand, anchored everything that we can know in human reason (mind and intuition), but could not demonstrate any fundamental justification for belief in first truths, being clearest only in the logical relations among beliefs. In a way, both positions had been reduced to skepticism, and Hume made that position explicit.
Kant's brilliance lies in the distinctive way in which he sought to resolve these conflicts. First, he chose to adopt the Empiricist position that (almost) everything we can know is presented to us in experience --- the phenomenal world. This confirms the basic subject matter of science. But the problem with this position was always its difficulty with generality, what Kant came to call the "synthetic a priori." Here Kant borrowed from the opposing point of view, Rationalism, and presumed to demonstrate ways in which the pure reason itself presents us with these contents. With the truth of both particulars and principles certain, science could continue upon a firm foundation. Interestingly enough, philosophers and scientists interested in the foundations of science were not themselves strongly influenced by Kant. The 19th Century was dominated by three schools of thought --- the Mechanical Materialists (a naive metaphysic popular with physical scientists), the Positivists (a methodological school intellectually stemming from the French Revolution), and Kantianism (by far the weakest of the three).
Kant's analysis of these issues was not without cost to traditional ideas. While he secured knowledge in the phenomenal world, he denied that we can have any knowledge at all of the noumenal world --- that whole (presumed) world of objects that exist yet without being presented to us in experience. Thus, he set himself (and others) the problem of rebuilding whatever one could of all those religious, social, and political ideas that were traditionally guaranteed by the noumenal world of gods and souls. At the same time, his solution to the problem of generality seemed to give free reign to features of the mind. If the mind's structure could guarantee certain general truths, why couldn't we, in fact, transform the world by discovering new structures of thought. Romanticism was a broad movement throughout the early 19th Century, affecting philosophy, literature, and the arts, and its groundwork was (romantically) derived from Kant.
The questions that Kant asks in his Prolegomena are how metaphysics is possible and whether it can be made into a science. To advance this inquiry, Kant assumes that mathematics and physical science are possible; thus, if he can determine how they are possible, then he will have a device for determining answers to his general questions about metaphysics.
What traditional discussions have demonstrated is that much of what we take to be certain, or necessary, is known a priori and is analytic. That is, its certainty precedes any experience and comes from the concepts involved themselves. At the same time, science contains enormous amounts of knowledge that derives from experience, that is, a posteriori and that is about the world or not merely derived from the initial concepts involved, what he called synthetic. Unfortunately, this cannot be the entire story because we believe that science presents us with knowledge of necessities; in other words, science as we know it, seems to contain specific kinds of general, necessary truths that are a priori and synthetic. The general problem, then, becomes the specific problem of discovering how synthetic a priori knowledge is possible in pure mathematics and, then, in pure physical science.
Kant proceeds by identifying pure mathematics as the science of space (geometry) and time (arithmetic). The theorems of geometry are known with necessity and they are about the world of geometrical objects in that schematic sense that we do not have to inspect particular objects to understand their truth. How can this be? The answer that Kant puts forward is that objects are presented to us through the sensuous intuition and that the theorems of geometry belong to the form of sensuous intuition in that sense that we cannot experience objects except as they adhere to these laws. The synthetic a priori character of geometry is determined by the fact that we cannot experience objects in any other way; this is the sensuous form in which objects are presented to our consciousness. Likewise, arithmetic, Kant believes, reflects the form of sensuous intuition with respect to time, or succession. The relations of numbers cannot be otherwise, because the numerical concepts as they relate to succession cannot be realized by us in any other way.
Turning to pure physical science, Kant recognizes that generality enters because of the way in which we reason. Thus, he begins with twelve categories of judgment and determines twelve corresponding forms of reason that must account for these. In a way that is exactly analogous to mathematics, science must see causality, for instance, because that is the way in which reason presents us with sequences of objects. We cannot experience sequences of objects without placing them in necessary causal frameworks. To imagine the possibility of experiencing objects that disobey mathematics or the pure principles of science would be to imagine an experience that is presented to us in an entirely different form of either sensuous or rational intuition. And that, of course, is impossible because this is the only world of intuitions that we know.
At this point, Kant is finally ready to ask whether metaphysical knowledge is possible. Having exhausted sensuous intuition of space and time and rational intuition of objects and their relations, he imagines that only pure reason itself remains. Thus, are there any propositions that seem to compel us on the basis of pure reason alone? Kant believes that there are such propositions, or ideas, and that they have been, historically, the very impulses that have inspired metaphysical speculations. They are the psychological, cosmological, and theological ideas --- that is, ideas about self, reality, and supreme beings. In the analysis that follows, Kant makes it clear that there must be a sense in which genuine metaphysical ideas are possible for each of these categories but that these ideas cannot (must not) go to the extreme of naming and describing noumenal objects. In particular, we engage in absurdity, according to Kant, when we attribute predicates to noumenal objects. The whole meaning of one of these metaphysical ideas, then, must rest back in the phenomenal world and be a necessary "finishing off" of all our experiences in that world as pure reason demands.
At the very end, Kant can ask the final question, whether a science of metaphysics is possible. The answer to this is negative since we can have no experience of these metaphysical entities. They are merely products, indescribable, of pure reason itself. Metaphysics, then, rests in a very uncomfortable place after Kant has dealt with it. Souls, physical reality, and God have only a very slight and rather insignificant possibility as abstract "finishing concepts" whose entire meaning comes out of the phenomenal world that we experience.
Kant's Prolegomena set a desperate problem for the moral life of humans. Europeans had been Christian for longer than anyone could conceivably remember and the starting point of Christian morality lay in the idea that humans must be told how to live. Morality, thus, is delivered by prophets or by God Himself. The traditional Catholic understanding, for centuries, was that God informs the Pope and the Pope writes "homilies" that interpret Divine principles into the human context for Bishops and Priests to convey to their flocks. An individual must accept the word of God as spoken to him/her by the Priest as the law of human behavior. The moral life is to live by these Divinely inspired laws. Traditional Christianity had been under criticism in many ways, of course, since the early 16th Century so Kant's philosophical position was no unique revolution. However, Kant's position takes the discussion to the final edge; he denies God as anything that we can know and allows only for a "supreme being" produced by the pure reason and merely summing, or finishing, all the relevant materials of experience. The supreme being, in other words, can offer us nothing that we do not already have. The moral life, if it is to exist at all, must be found within human experience. We will see this issue arise again-and-again throughout the 19th Century.
Kant's argument is broken into three systematically separate sections. The first is a discussion of common-sense, practical morality that introduces the philosophical problem. The second, is a discussion of a new metaphysical basis of morality. Finally, this is rounded out with a critical examination of pure practical reason.
Kant begins with the concept of will as the central medium of human action. Thus a good person is a person whose will is good; but common sense suggests that a truly good person would have a will that is good in itself in that ultimate sense that it is not swayed in its goodness by mere ends. For the truly good will, there must be a principle in the willing itself and that is independent of ends that we might entertain and that determines action in accordance with principle. We should see already that, if Kant can make clear the experiences that we have with this pure practical reason, there will be a metaphysical idea standing just outside of our experience that completes these in a whole thought and that is, then, the basis of human morality. For the time being, he uses the concept of duty to point to these experiences, urging us to focus on only acts in accordance with duty as possessing moral worth. All other acts involve ends of different kinds and, consequently, require determination of facts derived from experience as part of the willing process.
A metaphysics of morals is required as the "indispensable substrate of all theoretically sound and definite knowledge of duties," hence, moral worth (410). This is because only a metaphysics of morals can deliver synthetic a priori knowledge of moral action, replacing the necessity of Divine laws. The human problem, in other words, is to replicate Divine certainty with only human means. In a crucial section (412), Kant observes that all the objects of nature obey laws but only rational beings have "the capacity of acting according to the conception of laws." This is what Kant calls "will" and "it is nothing less than practical reason." Notice that Kant has merely used the word "capacity" here. In other words, the will has the capacity to conceive of objective laws of action but does not necessarily have to be compelled by them. Those laws come in the form of commands, or imperatives, but the will does not obey them by necessity. Clearly, this is the basis on which we can talk about a good will or a bad one. Objective laws, or imperatives, can be either hypothetical or categorical, Kant concludes. An hypothetical imperative simply claims that one must act in a certain way in order to achieve some end. A law of this kind is clearly synthetic a posteriori, like most natural laws. A categorical imperative, on the other hand, is a synthetic a priori law, presenting "an action as of itself objectively necessary."(414) This, clearly, is the kind of law that Kant needs to characterize his concept of moral worth, which is an action that has no regard for ends but only for its own necessity.
After some discussion, Kant separates out three kinds of principles: rules of skill, counsels of prudence, and commands of morality. These are the technical, pragmatic, and moral commands that practical reason deals with. Clearly, the moral commands are the important ones for this text. From 419 through 426, Kant explores the nature of the categorical imperative and offers examples. The key concept here is that an action which is authentically moral must be capable of being thought or willed as a universal law of human action without regard to ends (other than happiness). In the remainder of the second section, he continues the development of his moral concepts, beginning at 427 where he returns to the metaphysics of morals. At issue is the concept of the will in relation to the imperatives. In particular, Kant asks, is there a law that commands the will to be good, that is, that commands obedience to categorical imperatives? If there is no such principle, then morality would seem to be a subjective choice.
The crucial development of this idea comes at 428 where Kant grasps that the key to such a law would be a human end that is an "end in itself." What would such an end of human action be? The answer is clear that it would be achieving our "rational nature," for "man and, in general, every rational being exists as an end in himself and not merely as a means to be arbitrarily used by this or that will." Thus, Kant advances the practical imperative which must determine the will itself in obeying moral laws: "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." It is in this sense that the bad will violates a law by not obeying a categorical imperative of action since, in doing so, it turns away from treating itself only as an end, and acts in favor of lesser ends.
Let us review and summarize the situation. All categorical imperatives are synthetic a priori commands (laws) upon the will, bearing moral weight. The will, however, is unlike other natural objects in that it does not have to behave according to law. Thus, Kant needs to demonstrate that there is at least one categorical imperative that commands the will to obey all categorical imperatives; otherwise, morality is merely subjective. The nature of such an imperative would be something that is synthetic a priori, that is, a judgment that we recognize as true and substantive, immediately and with necessity. Kant's "principle of humanity," above, is proposed as such an imperative. Clearly, it goes beyond the former imperatives which were specifically directed at actions; this principle is directed at all actions with respect to the nature of human action itself. Kant calls it "the supreme limiting condition on the freedom of action of each man." (431) Thus, it proposes a limitation on the will's freedom of obeying imperatives of action or not.
To make this discussion somewhat more clear, Kant suggests what he calls the "realm of ends." The realm of ends is a systematic union of all rational beings along with the ends that they entertain through their actions. "Morality," then, "is the condition under which alone a rational being can be an end in himself, because only through it is it possible to be a lawgiving member of the realm of ends." (435) Thus, only humanity can have dignity and, that, by embracing morality. Kant's formula, here, has a very interesting relation to political philosophy of the "social contact." The idea is implicit in the combination of practical reason understanding laws as universal propositions and reason itself being the nature of humanity as its only end. "The will is not only subject to the law," Kant says (431), "but subject in such a way that it must be conceived also as itself prescribing the law." In social-contract theory, the people are held accountable to civil law because they are conceived to be the authors (by contract) of that law. Kant's realm of ends, he says, is analogous to the realm of nature, only the realm of ends is possible through self-imposed maxims that treat humanity as an end and the realm of nature is possible through "laws of efficient causes of things externally necessitated." (438)
In the third section, Kant brings all of these discussions together. In particular, he identifies the two standpoints from which any person must view himself: "first, as belonging to the world of sense, under the laws of nature . . . and, second, as belonging to the intelligible world under laws which, independent of nature, are not empirical but founded on reason alone." It is in this second standpoint that Kant believes "man cannot think of the causality of his own will except under the Idea of Freedom." (452-3) Kant's summary of these ideas is telling. "Thus categorical imperatives are possible because the Idea of freedom makes me a member of an intelligible world. Consequently, if I were a member of that world only, all my actions would always be in accordance with the autonomy of the will. But since I intuit myself at the same time as a member of the world of sense, my actions ought to conform to it, and this categorical 'ought' presents a synthetic a priori proposition." (454) He continues, "man, who in this way regards himself as intelligence, puts himself in a different order of things and in a different relationship to determining grounds." (457) And, "moreover, since it is only as intelligence that he is his proper self (as man he is only appearance of himself), he knows that those laws apply to him directly and categorically." It is the Idea of Freedom, Kant concludes, that makes the categorical imperative possible to man.
Notes:
(1) The term metaphysics originally referred to the writings of Aristotle that came after his writings on physics, in the arrangement made by Andronicus of Rhodes about three centuries after Aristotle's death. In the books named "Physics" by Andronicus, Aristotle dealt with natural objects and processes, that is, those things that we experience around us. In the books that Andronicus named "Metaphysics," Aristotle dealt with certain general ideas, objects, and processes which standard unexperienced behind the whole.
Plato was not satisfied that we can know anything about the objects that we experience because these objects are in constant change. As a consequence, Plato engaged in metaphysics by describing various objects which he thought to be permanent and unchanging. These were the Ideas and Souls. He alleged that Ideas can be known. In fact, he thought they were the only real things and that objects of experience were merely appearances. We have to be careful how we use the term 'real' in this context, however, because others have argued that experienced objects are the only realities. It is also not entirely clear that a person discussing unexperienced objects needs to claim that they are real. So-called "instrumentalists" in science have proposed that their talk about unexperienced entities, properties, and processes needs only to be useful in the experienced world and need not be judged as a description of reality. It remains metaphysical, however, even if it is only instrumental in intention.
Metaphysical commitments run closely connected to our concepts of what we can know and how we can know anything about these things. Thus, metaphysics and epistemology (see next note) are very closely connected.
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| a priori | a posteriori | |
| analytic | all statements that come from mere definitions of terms | nothing |
| synthetic | pure mathematics pure natural science all of metaphysics |
most of what we know about the world |
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Be sure to visit Kant on the Web and the Study Place: Kant.
Sources: W. T. Jones. A History of Western Philosophy, Vol. 4, Kant and the 19th Century (Harcourt, Brace, Jovanovich, 1975) and "Sketch of Kant's Life and Work" in Kant. On History, edited by Lewis White Beck (Bobbs-Merrill, 1963).
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