Kant′s Account of Reason.doc

Kants Account of ReasonFirst published Fri Sep 12, 2008; substantive revision Tue May 12, 2009Two of the most prominent questions in Kants critical philosophy concern reason. The first, central to his theoretical philosophy, is the unprovable pretensions of reason in earlier “rationalist” philosophers, especially Leibniz and Descartes. The second, central to his practical philosophy, is the subservient role accorded to reason by the British empiricistsabove all Hume, who declared, “Reason is wholly inactive, and can never be the source of so active a principle as conscience, or a sense of morals.” (Treatise, 3.1.1.11; see also the entry on Rationalism vs. Empiricism.) Thus the titles of two key works: the monumental Critique of Pure Reason, and the Critique of Practical Reason that is middle point of his great trio of moral writings (between the Groundwork of the Metaphysics of Morals and The Metaphysics of Morals).It is clear that practical reason is the foundation of Kants moral philosophy. It is less clear what role reason plays in his theoretical philosophy. Kant insists that “metaphysics is utterly impossible, or at best a disorderly and bungling endeavour” if we do not separate “ideas of reason” from “concepts of the understanding” (Prolegomena 41, 4:329). But while he emphasises the solidity of the empirical knowledge gained via the latter, reason often appears to be merely a source of error and illusion. (This is especially so with regard to the most-read sections of the first Critiquethe Aesthetic, Analytic and Dialectic.) But if this were so, the status of philosophical reasoning itself would stand in grave doubt. In addition, we might note that Kant rarely discusses reason as such. This leaves a difficult interpretative task: just what is Kants general and positive account of reason?This entry has the following structure. The first section sets out the role that reason plays in Kants account of knowledge and metaphysics in the first Critiquesomething that is relatively uncontroversial in the secondary literature. The second section examines key aspects of reason in the moral philosophy, with especial reference to the second Critique. Reflecting Kants canonical texts and the bulk of the secondary literature, these discussions of theoretical and practical reason are relatively independent of one another. The third section, therefore, considers how Kants views of theoretical and practical reason may be related, emphasising especially the most prominent contemporary interpretation of Kantian reason, that of Onora ONeill. The concluding remarks emphasise the potential philosophical interest of such a unified interpretation of Kants account of reason. 1. Theoretical reason: reasons cognitive role and limitations o 1.1 Reason as the arbiter of empirical trutho 1.2 Reason in scienceo 1.3 The limits of reasono 1.4 Reasons self-knowledge 2. Practical reason: morality and the primacy of pure practical reason o 2.1 Freedom implies moral constraint in the form of the categorical imperativeo 2.2 How moral constraint implies freedom: Kants “fact of reason”o 2.3 The primacy of practical reason 3. The unity of theoretical and practical reason o 3.1 Reasons “common principle”o 3.2 The “maxims of common human understanding”o 3.3 The public use of reason and the importance of communication 4. Concluding remarks Bibliography o Primary sourceso Secondary literature Other Internet Resources Related Entries1. Theoretical reason: reasons cognitive role and limitationsThe first half of the Critique of Pure Reason argues that we can only obtain substantive knowledge of the world via sensibility and understanding (roughly, our capacities of sense experience and concept formation). The next large sectionthe “Transcendental Dialectic”demolishes reasons pretensions to offer knowledge of a “transcendent” world, that is, a world beyond that revealed by the senses. (“Dialectic,” says Kant, is “a logic of illusion” (A293): so in his vocabulary, a dialectical idea is empty or false.) However, the Critique of Pure Reason should not be read as a demolition of reasons cognitive role. Kant certainly wants to delimit the bounds of reason, but this is not the same as arguing that it has no role in our knowledge. Three points are crucial: (1.1) the relation of reason to empirical truth; (1.2) its role in scientific enquiry; and (1.3) the positive gains that come from appreciating reasons limits.1 In addition, sound philosophical reasoning requires that reason gain knowledge of itselfa task that is begun, but not completed, in the first Critique (1.4).1.1 Reason as the arbiter of empirical truthThe first thing to observe is that Kant explicitly says that reason is the arbiter of truth in all judgments. Unfortunately, he barely develops this thought, and the issue has attracted surprisingly little attention in the literature. (But cf. Walker 1989: Ch. 4; Guyer and Walker 1990; Kants Theory of Judgment, 1.3, 1.4).2 However, some basic points are clear from the text. We form judgments about the world around us all the time, without a second thought: we see a hand in front of us and judge it to exist; after a dream, we judge ourselves to have been dreaming and the dreams contents to be illusory; we see the sun rise and assume that it orbits the earth. A large part of Kants philosophical efforts are devoted to showing that all these judgments rely on categories, such as cause and effect, that must order our sensory impressions. Only if a belief conforms to these conditions does it meet the “formal” conditions of truth. (Nonetheless, unless we are fundamentally confused about something, all our beliefs meet this formal condition.3) But there is a further question: which of our beliefs are actually (or “materially”) true, and which erroneous?Kant begins with the observation that only once there is judgment can there be error: “It is correctly said that the senses do not err; yet not because they always judge correctly, but because they do not judge at all” (A293). For example, there is no error involved in the impressions of a dream, simply as such. But if someone were to get confused about her dreamed experience, and suppose that it had really happened, then she would be making a judgmentand a false one too. So Kant claims, “error is only effected through the unnoticed influence of sensibility on understanding, through which it happens that the subjective grounds of the judgment join with the objective ones” (A294). In the example, someone confuses a subjective ground of judgment (“I had this dream”) with an objective one (“these events took place”).4How does reason enter the matter? Kant says the following: “For the law of reason to seek unity is necessary, since without it we would have no reason, and without that, no coherent use of the understanding, and, lacking that, no sufficient mark of empirical truth” (A651=B6795). For example, suppose our dreamer believes she has won a lottery, but then starts to doubt this belief. To decide the truth, she must ask how far the belief connects up with her other judgments, and those of other people.6 If it fails to connect up (we check the winning numbers, say, and see no match with the actual ticket), she must conclude that the belief was false. Or consider why we are sure that the sun does not orbit the earth, despite all appearances. Such a judgment cannot be squared with all our other judgments about the motions of planets and stars, judgments that have been unified by reason in the form of laws of gravity, momentum and so forth. It is in these unifying laws, discovered by Newton, that Kant sees proper confirmation of Copernicus heliocentric hypothesis (Bxxii n; cf. 1.4 below), not in Galileos observations of the heavens with the telescope. Consistency in observations is generally sufficient to confirm everyday knowledge claims. Scientific knowledge aspires to law-like completeness (e.g. the motion of all heavenly objects, and not only the movement of the sun relative to the earth).1.2 Reason in scienceThis brings us to the second key point offered in the Critique: reasons role in scientific knowledge. For information about the world, we are entirely dependent on sensibility and understanding. Nevertheless, reason is “the origin of certain concepts and principles” (A299/B355), leading Kant to define it as a “faculty of principles” (A299/B356) or the “faculty of the unity of the rules of understanding under principles” (A303=B358). The question for Kant is whether and how these concepts and principleswhich he subsequently terms “transcendental ideas” (A311/B368)might be justified.Apart from ideas about objects that lie beyond sensory experience, such as God or the soul, we also form transcendental ideas about entities that are meant to constitute the ultimate basis of everything that might be experienced, such as the universe as a whole: Kant speaks of “world wholes” or cosmological ideas. Claims to objective knowledge about these cosmological ideas, such as the claim that the universe has a beginning in time or the opposing claim that it does not, inevitably lead usor so Kant arguesinto contradictions or “antinomies.” Yet science itself assumes that the world forms a well-ordered, systematic unity whereby all events can be subsumed under causal laws. Evidently, no set of experiencesnecessarily finite in extentcould ever correspond to this apparently cosmological claim. Kant argues, however, that reason is justified in adopting certain principles concerning the ultimate basis of our experience of the world, so long as it does not treat these as knowledge claims. This is his distinction between the “constitutive” and “regulative” use of ideas. (See e.g. Buchdahl 1992; Friedman 1992c.)Rather than being a source of knowledge (“constituting” it), reason indicates how we should proceed with (“regulate”) the knowledge we do have, so as to correct errors and achieve more comprehensive insights. Activities must have goals if they are not to degenerate into merely random groping (cf. Bvii, A834=B862); reasons is that of unity. When Kant speaks of the “unity of reason” in the first Critique, he means that reason gives “unity a priori through concepts to the understandings manifold cognitions” (A302/B359; cf. A665=B693, A680=B780). This unity must be a priori since it cannot be given through any set of experiences. Instead it is presupposed: as applied to science, it is the task of looking for the greatest possible completeness and systematicity (cf. Guyer 1989), subsuming objects and events under the most all-encompassing laws. We do not know in advance how far we will succeed, or that nature is wholly law-like, but the principle that unity is to be sought after nonetheless forms (what Kant calls) a “maxim” or regulative principle of reason (A666=B694). By contrast, the claim that such unity does exist would represent a “constitutive principle,” the sort of “cosmological” knowledge claim that we cannot justify.Kants account of science, and especially the role of “teleological” or purposive judgment, is further developed in the Critique of Judgment. See Guyer 1990, Freudiger 1996, and Nuzzo 2005, as well as Kants Aesthetics and Teleology, 3. On Kants account of science more generally, see Wartenberg 1992, and Buchdahl 1992; on reason and science, see Neiman 1994: Ch. 2. The entry on Kants Philosophy of Science considers Kants view of the natural sciences, especially physics.1.3 The limits of reasonThe third point is the most well-known, and is considered in detail in the entry on Kants Critique of Metaphysics. Kant demolishes a series of supposed proofs of the existence of God (“The Ideal of Pure Reason”) and the soul (“The Paralogisms”). He also demonstrates that we can just as well prove certain “world wholes,” such as unbounded space, as their opposites (“The Antinomies,” including the idea of an absolutely first cause: the problem of freedom as it is posed in the famous “Third Antinomy”). These sections have always been regarded as among the most convincing parts of the first Critique. Mendelssohn spoke for many of Kants contemporaries in calling him the “all destroyer,” for devastating reasons pretences to transcendent insight.Kant is certainly engaged in clearing the ground, but the exercise is not merely destructive. Not only is reasons self-knowledge at stake (1.4); in addition, Kant sees that the failure to establish secure groundas to what we can knowhas been more damaging than any critique. In the hands of theologians and metaphysicians, reason has claimed knowledge that it cannot have, leading to empty battles of competing positions that invite outright scepticism. At the beginning of the Doctrine of Method (the last, least-read part of the first Critique) Kant alludes to the biblical story of Babel.7 God punished the attempt to build “a tower that would reach the heavens” (A707=B735) with a confusion of languages, leaving people unable to understand one another and unable to cooperate in such hubristic ventures.8 Again and again, reason dreams up variations on some very basic ideasthe immortal soul, God, freedom; what is more, it cooks up9 more or less convincing proofs of these. Without the acid test of experience of a common world, people are bound to come up with conflicting versions of these ideas. Then they will either talk past one another, or fall into conflictor, one of Kants most abiding fears, be forced to submit to an unreasoned authority. In metaphysics, Kant refers to “the ridiculous despotism of the schools” (Bxxxv).10 When we turn to the practical sphere, however, despotism is far from ridiculous: it is the last, brutal resort for securing some sort of coexistence among people who will not cooperate. Thus Kant often alludes to Hobbes, on whose theory peaceful order is only possible if an unaccountable sovereign power overawes all the members of society.11 Interpretations that see Kantian reason as securing intersubjective order, so as to overcome threats of Babel-like hubris, conflict and despotism, include Saner 1967, ONeill 1989, and Neiman 1994.One of the most famous lines of the first Critique occurs in the second editions Preface, where Kant says, “I had to deny knowledge in order to make room for faith” (Bxxx). Knowledge of the world as a whole, or of entities that transcend this world (the immortal soul or God) is not humanly possible: it is not possible via experience, and reason has no power to supply knowledge in its place. However, as indicated in 1.2, Kant argues that science is entitled to rely on certain principles that regulate its project, without yet being known as objects. In the final section of the Critique, Kant argues that knowledge is not the only end of reason: in its practical use, reason addresses our role within the world. It is this end that leads human beings to the ideas considered in the Dialectic.Thus Kant proposes three questions that answer “all the interest of my reason”: “What can I know?” “What must I do?” and “What may I hope?” (A805=B833). We have seen his answer to the first question: I can know this world as revealed through the senses, but not the total sum of all that is (since the senses never reveal that) nor a world beyond this one (a supersensible world). Kant does not answer the second question until the Groundwork to the Metaphysics of Morals, four years later. (Arguably, he sees no need to answer the question in this form, since he is confident that people have long known what their duties consist in.12) But he does include some observations on hopethat is, faith in God and a future world. We certainly fall into error if we think reason can know a world beyond the senses. Indeed, Kant insists that such knowledge would corrupt practical reasoning, by imposing an external incentive for moral actionfear of eternal punishment and hope of heavenly reward, what he will later call “heteronomy.” Nonetheless, human reason still has an unavoidable interest in belief in God, immortality and freedom. Kant develops this claim more systematically in the second Critique, as discussed below (2.3).Kants idea that reason has “interests,” or even “needs,” may seem strange, and is discussed by Kleingeld 1998a. For finite beings, reason is not transparently or infallibly given to consciousness (as some rationalist philosophers seemed to think), just as it cannot deliver transcendent truths. Thus reason “needs to present itself to itself in the process of gaining clarity about its own workings” (1998a: 97). That is, as the next section discusses, Kant views reason as essentially self-reflexive.1.4 Reasons self-knowledgeThe first Critique argues that metaphysicians have hitherto made no discernable progress in their enquiries. In the second edition Preface, however, Kant proudly proclaims that his book has put metaphysics on “the sure path of a science” (Bvii; cf Axiii). What, then, is the relation of metaphysicsor philosophical reasoning more generallyto those areas of human enquiry that do seem to generate certainty (geometry and mathematics) and the expansion of knowledge (science in general)?Kant had long been clear that mathematics could provide no model for philosophising.13 “Mathematics gives the most resplendent example of pure reason happily expanding itself without assistance from experience” (A712=B740). Though it would dearly love to do so, metaphysics cannot follow its course. This is not simply a rhetorical point, since many early modern philosophers had tried to do exactly thisSpinozas Ethics is one example, Hobbess political philosophy another (“so many houses of cards,” in Kants viewA727=B755). Kants basic argument is that mathematicians are justified in constructing objects or axioms a priori, becau