A Commentary to Kant's 'Critique of Pure Reason'

by Norman Kemp Smith

This Preface to the first edition, considered as introductory to the Critique, is misleading for two reasons. First, because in it Kant is preoccupied almost exclusively with the problems of metaphysics in the strict ontological sense, that is to say, with the problems of the Dialectic. The problems of the Analytic, which is the very heart of the Critique, are almost entirely ignored. They are, it is true, referred to in A x-xi, but the citation is quite externally intercalated; it receives no support or extension from the other parts of the Preface. This results in a second defect, namely, that Kant fails to indicate the more empirical features of his new Critical standpoint. Since ultimate reality is supersensuous, metaphysics, as above conceived, can have no instrument save pure reason. The subjects of its enquiry, God, freedom, and immortality, if they are to be known at all, can be determined only through a priori speculation. This fact, fundamental and all-important for Kant, was completely ignored in the popular eclectic philosophies of the time. They professed to derive metaphysical conclusions from empirical evidence. They substituted, as Kant has pointed out,[83] “a physiology of the human understanding” for the Critical investigation of the claims of reason, and anthropology for ethics. They were blind to the dogmatism of which they are thereby guilty. They assumed those very points which most call for proof, namely, that reason is adequate to the solution of metaphysical problems, and that all existence is so fundamentally of one type that we can argue from the sensuous to the supersensuous, from appearance to reality. When they fell into difficulties, they pleaded the insufficiency of human reason, and yet were all the while unquestioningly relying upon it in the drawing of the most tremendous inferences. Such, for instance, are the assumptions which underlie Moses Mendelssohn’s contention that since animals as well as men agree in the apprehension of space, it must be believed to be absolutely real.[84] These assumptions also determine Priestley’s assertion that though every event has its cause, there is one causeless happening, namely, the creative act to which the existence of the world is due.[85] On such terms, metaphysics is too patently easy to be even plausible. “Indifference, doubt, and, in final issue, severe criticism, are truer signs of a profound habit of thought.”[86] The matter of experience affords no data for metaphysical inference. In the a priori forms of experience, and there alone, can metaphysics hope to find a basis, if any basis is really discoverable.

This is Kant’s reason for so emphatically insisting that the problem of the Critique is to determine “how much we can hope to achieve by reason, when all the material and assistance of experience is taken away.”[87] But in keeping only this one point in view Kant greatly misrepresents the problems and scope of the Critique. Throughout the Preface he speaks the language of the Aufklärung. Even in the very act of limiting the scope of reason, he overstresses its powers, and omits reference to its empirical conditions. It is well to contrast this teaching with such a passage as the following:

“The position of all genuine idealists from the Eleatics to Berkeley is contained in this formula: ‘All cognition through the senses and experience is nothing but mere illusion, and only in the ideas of pure understanding and Reason is there truth.’ The fundamental principle ruling all my idealism, on the contrary, is this: ‘All cognition of things solely from pure understanding or pure Reason is nothing but mere illusion, and only in experience is there truth.’”[88]

But that passage is equally inadequate as a complete expression of Kant’s Critical philosophy. The truth lies midway between it and the teaching of the Preface to the first edition. Pure reason is as defective an instrument of knowledge as is factual experience. Though the primary aim of metaphysics is to determine our relation to the absolutely real, and though that can only be done by first determining the nature and possible scope of a priori principles, such principles are found on investigation to possess only empirical validity. The central question of the Critique thus becomes the problem of the validity of their empirical employment. The interrelation of these two problems, that of the a priori and that of experience, and Kant’s attitude towards them, cannot be considered till later. The defects of the Preface to the first edition are in part corrected by the extremely valuable Preface substituted in the second edition. But some further points in this first Preface must be considered.

Prescribed by the very nature of reason itself.[89]—Metaphysics exists as a “natural disposition,” and its questions are not therefore merely artificial.

“As natural disposition (Naturanlage) ... metaphysics is real. For human reason, without being moved merely by the idle desire for extent and variety of knowledge, proceeds impetuously, driven on by an inward need, to questions such as cannot be answered by any empirical employment of reason, or by principles thence derived. Thus in all men, as soon as their reason has become ripe for speculation, there has always existed and will always continue to exist some kind of metaphysics.”[90]

Hence results what Kant entitles transcendental illusion.

“The cause of this transcendental illusion is that there are fundamental rules and maxims for the employment of Reason, subjectively regarded as a faculty of human knowledge, and that these rules and maxims have all the appearance of being objective principles. We take the subjective necessity of a connection of our concepts, i.e. a connection necessitated for the advantage of the understanding, for an objective necessity in the determination of things in themselves. This is an illusion which can no more be prevented than we can prevent the sea from appearing higher at the horizon than at the shore, since we see it through higher light rays; or to cite a still better example, than the astronomer can prevent the moon from appearing larger at its rising, although he is not deceived by this illusion.... There exists, then, a natural and unavoidable dialectic of pure Reason, not one in which a bungler might entangle himself through lack of knowledge, or one which some sophist has artificially invented to confuse thinking people, but one which is inseparable from human Reason, and which, even after its deceiving power has been exposed, will not cease to play tricks with it and continually to entrap it into momentary aberrations that will ever and again call for correction.”[91]

Dogmatism.[92]—According to Kant there are three possible standpoints in philosophy—the dogmatic, the sceptical, and the critical. All preceding thinkers come under the first two heads. A dogmatist is one who assumes that human reason can comprehend ultimate reality, and who proceeds upon this assumption. He does not, before proceeding to construct a metaphysics, enquire whether it is possible. Dogmatism expresses itself (to borrow Vaihinger’s convenient mode of definition[93]) through three factors—rationalism, realism, and transcendence. Descartes and Leibniz are typical dogmatists. As rationalists they hold that it is possible to determine from pure a priori principles the ultimate nature of God, of the soul, and of the material universe. They are realists in that they assert that by human thought the complete nature of objective reality can be determined. They also adopt the attitude of transcendence. Through pure thought they go out beyond the sensible and determine the supersensuous. Scepticism (Kant, as above stated,[94] regards it as being in effect equivalent to empiricism) may similarly be defined through the three terms, empiricism, subjectivism, immanence. A sceptic can never be a rationalist. He must reduce knowledge to sense-experience. For this reason also his knowledge is infected by subjective conditions; through sensation we cannot hope to determine the nature of the objectively real. This attitude is also that of immanence; knowledge is limited to the sphere of sense-experience. Criticism has similarly its three constitutive factors, rationalism, subjectivism, immanence. It agrees with dogmatism in maintaining that only through a priori principles can true knowledge be obtained. Such knowledge is, however, subjective[95] in its origin, and for that reason it is also only of immanent application; knowledge is possible only in the sphere of sense-experience. Dogmatism claims that knowledge arises independently of experience and extends beyond it. Empiricism holds that knowledge arises out of sense-experience and is valid only within it. Criticism teaches that knowledge arises independently of particular experience but is valid only for experience.

The following passages in the Methodology give Kant’s view of the historical and relative values of the two false methods: