This series of lecture notes concludes with a look at Chapter II of the Transcendental Doctrine of Method, “The Canon of Pure Reason.” In this chapter is the most extensive discussion in the Critique of Pure Reason of practical reason and morality. Kant would go on to write a number of seminal works in ethics, including Fundamental Principles of the Metaphysics of Morals (1785), Critique of Practical Reason (1788) and The Metaphysics of Morals (1797).
The Critique of Pure Reason is divided into two parts, Transcendental Doctrine of Elements, and Transcendental Doctrine of Method. The former comprises Transcendental Aesthetic and Transcendental Logic, which includes the Analytic and the Dialectic. In the original edition, it encompasses nearly 700 pages. The Doctrine of Method, by contrast, is only about 150 pages in length.
The Doctrine of Elements is a survey of the suitability of the tools available for the construction of a system of pure theoretical reason. The system itself is developed in later works. In The Metaphysical Foundations of Natural Science (1786), Kant laid down the specific principles according to which experience is synthesized. The system of practical reason is found in The Metaphysics of Morals. This work contains a very extensive set of principles applying both to personal moral virtue (the “Doctrine of Virtue”) and to interpersonal justice (“The Metaphysical Elements of Justice”).
The overarching theme of the Doctrine of Method in the Critique is “the determination of the formal conditions of a complete system of pure reason” (A708/B736). It is divided into four chapters, “dealing with a discipline, a canon, an architectonic, and finally a history of pure reason” (A708/B736).
The discipline of pure reason concerns the way in which reason curbs its own pretensions. In the chapter on the discipline, Kant considers various methods that might be thought to extend or limit the reach of reason, and he argues that only critique provides reason with the proper self-discipline. The architectonic examines the structural features of a system of reason. The history gives a very brief look at some of the competing approaches to metaphysics before the dawn of critique.
Of concern here is the canon of pure reason. A canon is defined as “the sum of a priori principles governing the correct use of certain cognitive powers as such” (A796/B824). So general logic, with its forms of judgment and inference, is the canon for all use of the understanding and reason, respectively. Analytic, which is a kind of special logic, is the canon for the a priori synthetic principles of the understanding. Pure reason in its theoretical use (the subject-matter of the Transcendental Dialectic) has no canon, because it lacks valid a priori synthetic principles altogether. The only canon of pure reason concerns a priori principles governing the practical use of reason.
Kant begins his discussion of the principles of practical reason by posing the question of whether reason’s search for unity is driven by theoretical or practical interests. He answers that even if reason is successful in securing knowledge of its three objects, “the freedom of the will, the immortality of the soul, and the existence of God” (A798/B826), such knowledge is of no theoretical use.
Knowing that the will, as intelligible character, is free is of no use in understanding human behavior. For all events transpiring within the scope of experience can be understood in terms of natural laws. Knowing that the soul is immortal would tell us nothing about the character of existence beyond our lives in the empirical world. Even knowledge that there is a supreme creator and architect of the world would be of no value in the investigation of the world, other than in giving it general guidance in seeking causes. No specifics about exactly what purposes are at work in nature can be drawn from the fact that nature has an intelligent basis of order.
So, if the three ultimate objects of reason are to be of service at all, they would have to be considered from the practical point of view, which involves the ends for which rational action is undertaken. Some practical ends of reason are served by empirical rules of prudence, where “the entire business of reason consists in taking all the purposes assigned to us by our inclinations and uniting them in the one purpose, happiness, and in harmonizing the means for attaining this happiness” (A800/B828). By contrast, pure rules of practical reason would be moral laws, “which command not in an empirically conditioned, but in an absolute way” (A800/B828).
Returning to the three objects of reason, we find that they all are relevant to the practical question of “what is to be done” (A800/B828). In investigating this relation, it is important to exclude any empirical considerations. With respect to freedom, reason is not concerned with animal choice, which is determined entirely by sensuous impulses.
Instead, the practical question of what ought to be done concerns only practical freedom, which is manifest in experience. Practical freedom is the power to overcome sensuous impulse, based on “presentations of what is beneficial or harmful even in a more remote way” (A802/B830). This power is rational in that it involves deliberation. And it involves “laws of freedom” which tell us what ought to occur, as opposed to laws of nature, which tell us what occurs. The operation of these laws is independent of whether the human will is transcendentally free, a question which cannot be decided on the basis of pure reason in its theoretical use.
Now that he has established the theoretical uselessness of what would satisfy the practical ends of reason, Kant turns to the question of whether reason generates any ideas which would serve reason’s practical ends. If it does, then practical reason can be satisfied in a way that theoretical reason cannot.
In general, reason’s interest is in the answers to the following three questions (A805/B833).
The third question involves both practical and theoretical concerns, because it contains an implicit condition. Properly stated, the question is, if I do what I ought to do, what may I hope? The condition concerns morality, but the hope itself concerns existence, “that there is something” (A805/B833).
In the most basic sense, what one ought to do is to attain happiness, which Kant describes as “the satisfaction of all our inclinations” (A806/B834). We can obtain happiness if we behave prudently, that is, if we do what is necessary to satisfy our inclinations. The “ought” in this case is pragmatic, so that “the pragmatic law advises what we must do if we want to partake of happiness” (A806/B834).
A more refined sense of what one ought to do makes the goal not happiness, but worthiness to be happy. The “ought” which leads to worthiness of happiness is moral, and “the moral law commands how we ought to behave in order just to become worthy of happiness” (A806/B834). Whether one is worthy to be happy is independent of what one’s inclinations are and depends only on “the freedom of a rational being as such” (A806/B834). In this way, the moral law (if there is one) “can rest on mere ideas of pure reason and thus be cognized a priori” (A806/B834).
Kant goes on to assume that there is a moral law which is based in reason alone and which motivates the power of choice to act freely, independently of its inclinations. Such a law would command absolutely. It would be what Kant would in his ethical writings call a “categorical imperative.” There, he tries to give an a priori deduction of the moral law, but in the Critique he merely appeals to the authority of moralists and “the moral judgment that every human being makes if he wishes to think such a law distinctly” (A807/B835).
Now this purely practical use of reason is tied to an experience that is at least possible. Kant appeals to the principle that “ought” implies “can”: “since pure reason commands that such actions ought to occur, they must be able to occur” (A807/B835). The occurrence of what reason commands would have to take place in the experience of the human being. This gives the principles of pure reason in its moral use “objective reality” (A808/B836).
A generalization of the possibility of any individual moral imperative being carried out is the thought that all of moral imperatives are carried out. Thus, a moral world is possible. Such a world is merely intelligible, a mere idea, since we abstract from the sensible world all purposes based on inclination, as well as all other hindrances to the moral law’s being obeyed. “It is a practical idea that actually can and ought to have its influence on the world of sense, in order to bring this world as much as possible into accordance with the moral world” (A808/B836). This gives the practical idea “objective reality,” though not in the sense that it is an object of an intellectual intuition. Rather, it is a possible state of the sensible world.
Having established what one ought to do, from the standpoint of pure practical reason, Kant turns to the connection between the worthiness of happiness attained by following the moral law and actual happiness, which is what we hope for. Since happiness or lack of happiness is a factual state, it is the subject of theoretical reason. But theoretical reason can reveal no natural connection between the motivations of our actions and our happiness. It may hope for this connection “only if a supreme reason that commands according to moral laws is also laid at the basis of nature, as nature’s cause” (A810/B838).
Our hopes, then, rest with a being whose will is morally most perfect and who is most happy, and who through his recognition of the worthiness of happiness causes humans to be happy to the extent that they act morally. Kant had called a being whose character is determined by pure reason an “ideal.” So we have at the basis of our hope an ideal of the highest good. (Recall that an ideal is an object, or presentation of an object, that is thoroughgoingly determined and hence is an individual thing or presentation thereof.)
The moral world, as has been noted, is merely intelligible and is not revealed to the senses. Happiness in the sensible world is not proportional to morality. So we must think of the moral world as a future world, in which our actions in the world of experience lead to the proper measure of happiness. If the assumption of a future world is given up, one must “regard the moral laws as idle chimeras, because without this presupposition the necessary result that reason connects with these laws would have to vanish” (A811/B839). Only in this way can we regard the moral law as a command, carrying with it “promises and threats” (A811-2/B839-40).
Kant credits Leibniz with making a distinction very much like his own distinction between the sensible world and the intelligible moral world. These are in Leibniz’s terms the “kingdom of nature” and the “kingdom of grace,” respectively. (This idea basic goes back at least to Augustine in the fifth century CE. For Leibniz’s distinction as given in the “Monadology,” click here.) This is one of the places where Kant seems to be entirely in accord with Leibniz’s view.
Unless an intelligible moral world is assumed, there is no incentive to act upon the moral “ought.” However admirable we find the ideas of morality to be, it is the hope of happiness which gives us a practical motivation to live up to their lofty standards. Nonetheless, it is not the end of finding happiness that is originally responsible for the moral attitude, which is reverence for the moral law. It is the moral law which makes us worthy of happiness and thus gives us cause for hope that this happiness will be realized.
The highest good of the moral intelligible world is the exact conformity of happiness of human beings to the morality that makes them worthy of happiness. This must be distinguished from a being which is “a highest original good” (A814/B842)—an ideal of reason. This being is “a good where independent reason, equipped with all the sufficiency of a supreme cause, establishes, preserves, and completes—according to the most perfect purposiveness—the order of things that is universal although very much concealed from us in the world of sense” (A814/B842). Such a good would be “a single, rationally perfect, and rational original being” (A814/B842) and the object of a moral theology.
Morality alone can point us to such a being. Even the physicotheological proof, which postulates a rational basis for the order and purposiveness in the world, does not lead us to a single being in whom all purpose is united. (This point had been made by Hume in the Dialogues Concerning Natural Religion; Kant does not acknowledge Hume here, but he discusses the Dialogues extensively in the Conclusion of the Prolegomena, §§58-59, Ak 4:350-360.) But a unitary being is necessary if there is to be a source of a single purpose (to obey the moral law) in all wills.
Moral theology also calls for the original being to be omnipotent, able to bring about the conformity of virtue to happiness. It must also be omniscient, in order that the worthiness of all human beings can be known so as to allow the conformity to be brought about. It must as well be omnipresent, eternal, and so forth. In other words, it must be God. (Here, Hume would argue, Kant seems to be going too far, since he only needs to postulate powers sufficient to bring about the moral end.)
This moral theology leads as well to a transcendental theology. As morality dictates that we must conceive the world as unified with respect to moral purpose, reason generalizes the moral unity to “the purposive unity of all things making up this large whole according to universal natural laws” (A815/B843). The idea of universal purposive unity may be used theoretically to direct our investigation of nature. So this investigation is based on a transcendental theology, which is “not the cause but merely the effect of the practical purposiveness imposed on us by pure reason” (A817/B845). Kant makes the historical claim that humans’ conceptions of God were brought to their highest point through a growing awareness of the moral law, and not through theoretical speculation.
Kant ends his treatment of the highest good by rejecting what we now call a “divine command” account of morality. Since the ideal of the original being derives from the moral law, it cannot be used to derive the moral law. We should not “regard actions as obligatory because they are commands of God, but shall regard them as divine commands because we are intrinsically obligated to them” (A819/B847). Here Kant sides with Socrates against Euthyphro, and with Leibniz against Descartes and Newton. All we postulate of God is what serves the purposes of morality in the world in which we live. To base our notions of the divine will on anything but our knowledge of the moral law leads to “fanaticism or perhaps even wickedness,” which would “pervert and defeat the ultimate purposes of reason” (A819/B848).
The Canon of Pure Reason ends with a section discussing the related concepts of opinion, knowledge, and faith. The three share in common “assent,” or the holding of a judgment to be true. Assent is either persuasion or conviction. Persuasion is assent with only “private validity” (A821/B849). Conviction, on the other hand, is “valid for every human being’s reason” (A821/B849). We can test, to some extent, whether our assent is merely persuasion by seeing whether others assent to the bases of our own assent, which allows us to detect bias which would keep our assent from being conviction.
One holds an opinion when one’s assent does not rest on a basis that one finds to be secure. Opinion is a kind of preliminary assessment which is “subjectively insufficient” (A822/B850). Kant notes that there are no opinions in matters which are judged a priori, since in that case there are subjectively sufficient grounds for assent.
One may assent when one has a subjectively secure basis, even though one recognizes that this basis is not objective. The basis, in other words, is enough for my assent (conviction) but not enough to compel everyone’s assent. Objective sufficiency is called certainty. Conviction which falls short of certainty is what Kant calls “faith” (Glauben), which in some contexts is better translated as “belief.”
Knowledge is conviction which is at the same time certainty. The basis for one’s assent is both subjectively and objectively sufficient. Although there is knowledge through a priori judgment restricted to experience, there is no knowledge in the transcendental use of reason.
Most of the rest of the section is devoted to faith. Kant claims this kind of assent is peculiar to practical reasoning. Why otherwise would one assent to what one recognized has objectively insufficient grounds, unless assent were to serve a practical purpose? In cases of “pragmatic belief,” one acts on insufficient grounds because one must act. “A physician must do something for a patient who is in danger, but is not acquainted with the nature of the patient’s illness” (A824/B852).
Kant notes that pragmatic belief comes in degrees, which can be measured by one’s willingness to undertake a bet on whether the belief is true. The device of measuring degree of belief in practical matters can be extended to cases which could not involve action, as, for example, whether there are inhabitants on other planets. Conviction in these cases is called “doctrinal faith.”
The doctrine of the existence of God falls into this classification. As we have seen, it is based on the need of reason for a unifying explanation for purposiveness in nature. The doctrine of the future life of the human soul is also a matter of doctrinal faith, as it depends on “the superb endowment of human nature and the shortness of human life that is so incommensurate with this endowment” (A827/B855). But even though one may be convinced in these matters, without objective sufficiency there is still “something shaky” about merely doctrinal faith, since that conviction can be lost for a time, even though it inevitably returns (A827/B855).
A further type of faith, that rests on a very secure basis, is moral faith. The basis here is the certainty of the moral law, which must lead to conviction about the existence of God. “And I am sure that nothing can shake this faith; for that would overturn my moral principles themselves, which I cannot renounce without being detestable in my own eyes” (A828/B856). This faith survives the acknowledgment that speculative reason cannot give it an objective basis. A person of faith has a moral certainty, if not a “logical” certainty (A829/B857).
The only threat to moral faith is one’s abandonment of moral attitudes. Someone indifferent to the moral law will have no basis for moral faith, but would have to fall back onto doctrinal faith, which is vulnerable to “obstinate skepticism” (A830/B858). Still, even such a person has a practical interest in the existence of God, since he must fear the possibility of punishment in a future life. (Here, Kant echoes “Pascal’s wager.”) And he cannot be certain that there is no God or a future life. This fear-based faith is called “negative faith” (A830/B858).
We conclude with Kant’s last remark in the chapter. It may be objected that the only product of pure reason, which promises to open up to us realms beyond experience, is “nothing more than two articles of faith” (A830/B858). No philosopher is needed to uphold this kind of conviction, which is available to the common people. Kant responds that this is a good thing. We should hope that philosophy upholds common conviction, and we should be suspicious if the most important matters of life can be revealed only through deep philosophical investigation.
In closing, in the Canon of Pure Reason can be found the meaning of Kant’s famous pronouncment in the Preface to the second edition of the Critique. The problem with dogmatic metaphysics is that it attempts to understand God, freedom and immortality in terms of concepts that are suitable only for use in experience. Thus, metaphysics is forced to treat them as appearances or properties of appearances, which in turn leaves no space for practical morality.
I therefore had to annul knowledge in order to make room for faith. And the true source of all the lack of faith which conflicts with morality—and is always highly dogmatic—is dogmatism in metaphysics, i.e., the prejudice according to which we can make progress in metaphysics without a critique of pure reason. (Bxxx)Pure theoretical reason must be restrained in order that we might grasp the possibility of pure practical reason. Metaphysics must step aside in the interests of morality.