¹ Beck, Lewis White. A Commentary on Kant's Critique of Practical Reason. Chicago: University of Chicago Press, 1960. p. viiGoogle Scholar. The author qualifies this remark to the extent that no major and only one brief commentary has appeared.

² Schilpp, Paul A.. Kant's Pre-Critical Ethics. Evanston: Northwestern University Press, 1938. p. 14Google Scholar.

³ It is customary to cite the Critique of Pure Reason according to the original pagination of the first edition (“A” 1781) and the second edition (“B” 1787). The English translation of Norman Kemp Smith is that used in the body of this paper.

⁴ If ‘the idea of the whole’ is in the area of the practical employment of reason, then any historian who would emphasize the speculative elements of his thought (eg., Simel, Ernst Cassirer, Cohen, Natorp; sometimes called the ‘Marburg School’) to the neglect of the practical would be interpreting his thought by way of the use later philosophers made of it—a cardinal blunder for historians. If, on the other hand, the speculative interpretation of the unity of Kant's thought is well taken, then those who regard Kant as a moral philosopher (eg., Windelband, Rickert, Kroner; sometimes called the ‘Heidelberg School’) violate his position.

The results of this paper will show clearly that both schools of Kantian interpretation are inadequate. The speculative interpretation will be shown to be a violation at least of the unity of Kant's thought. Of the two, the practical interpretation is to be preferred.

Although there are many who advocate the practical interpretation of Kant's effort, their case lacks in either of two respects. On the one hand are those who posit the preferability of this position within the context of works directed to other points. The works of Beck and Schilpp already cited are examples of this type. Although their texts are well chosen, they have only the force of isolated remarks and are for that reason less than conclusive evidence in favor of the practical interpretation.

On the other hand are those whose interpretations are rich and full, but lacking almost entirely in direct textual verification. Such a work is Richard Kroner's Kant's Weltanschauung. Although the reader of this work achieves a certain sympathy with Kroner's thesis—‘the primacy of the practical’—he feels that that thesis does not spring directly from the pages of Kant. This distance from the texts, of course, is to be expected in a work which aims at setting down the ‘spirit and ethos’ of Kant's thought.

⁵ A brief critical history of scholarship which acknowledges these propositions as the key to the unity of Kant's thought can be found in Martin, G.. Kant's Metaphysics and Theory of Science. Lucas, P. G. (Transl.) Manchester: Manchester University Press, 1955, pp. 130–34Google Scholar. Martin goes on to indicate the inadequacy of his own synthesis. He moves from the hypothesis that Kant was working on ‘the question of being’ as stated in Aristotle and Aquinas. He admits that there is no direct textual justification for this hypothesis, (cf. p. 201)

⁶ In this regard Kroner criticizes Vaihinger's thesis that in the mind of Kant we must act ‘as if God exists.’ Kroner rejects this as groundless and goes on to show that the existence of God is postulated by practical reason. An examination of the text cited above will reveal that Vaihinger's thesis is not groundless. Speculative reason must accept the ‘idea’ of the existence of God in order to accomplish the speculative synthesis of empirical knowledge. In this respect Kant does insist that we proceed ‘as if God exists.’ Where Vaihinger fails is in not seeing that this is neither the last, nor the most significant word of Kant on this subject. This is merely the ‘negative’ element of Kant's treatment of this ‘idea’ in the first Critique. In this respect, Kroner's point is well taken. Nevertheless, once we see that Kant is exhibiting a dual treatment of this ‘idea’ in the first Critique, we must admit that there is no essential contradiction between the two positions when they are adequately considered.

⁷ It is customary to cite the second Critique and the Foundations according to the pagination of the Prussian Academy edition (volume and page). The English translation is that of Beck in his volume Immanuel Kant. Critique of Practical Reason and other writings in Moral Philosophy. Chicago: University of Chicago Press, 1949Google Scholar.

⁸ The transition from the moral law to the highest good is crucial to an understanding of Kant's postulation of the immortality of the soul and the existence of God. Kroner locates this transition in the moral imperative itself as postulating a transcendent realm which constitutes the unity of the realms of nature and freedom, (op. cit. pp. 32 and 54.) Beck, on the other hand, feels that this transition is based solely in the requirement of pure speculative reason for a complete system of ends. (A Commentary. … p. 245) This conclusion is based upon a supposed contradiction in Kant's doctrine between the ‘moral law’ as the sole determination of a good will and the ‘highest good’ as the adequate object of the moral law. According to Beck, Kant cannot at once hold that moral action is determined a priori and that the highest good is its “motive.” (Ibid. pp. 243–4) Accordingly, he goes on to allege that the postulates of immortality and God lack cogency except as required for the total system of ends.

Were Beck's criticism accurate, Kant's postulates of immortality and God would be grounded in the need for system and not in freedom as Kant has explicitly stated in the ‘Preface’ to the second Critique. Again, were this the case, scholars would be justified in restricting their attention to the Foundations when considering Kant's ethical doctrine. We believe, with Kroner, that this is not the case. In order to clarify this point we must re-examine Kant's texts as to the manner in which the moral law determines action.

The text under discussion at this point reads as follows: “The achievement of the highest good in the world is the necessary object of a will determinable by the moral law.” (V, 122) What is there about the moral law that requires the achievement of the highest good ? This is the point of Beck's criticism—nothing!

In the “Analytic” of the second Critique, Kant pointed out that moral activity is not based in an object considered as the determining ground of the faculty of desire. The moral law alone is such a ground. This discussion does not thereby deny all intelligibility to the notion of ‘object’ in moral matters. Consider his discussion of the notion of ‘object.” “By a concept of an object of practical reason I understand the idea of an object as an effect possible through freedom. To be an object of practical knowledge as such signifies, therefore, only the relation of the will to the action whereby it or its opposite is brought into being.” (V. 57)

Thus, while ‘object’ as the relation to action through sensuous desire is denied, ‘object’ as the relation to action through freedom is not denied. Rather, morality, according to Kant, retains the notion of acting for an object through directives. He indicated this in his discussion of the confusions of past philosophers on this point: “For they sought an object of the will in order to make it into the material and the foundation of the law … instead, they should have looked for a law which directly determined the will a priori and only then sought the object suitable to it.” (V, 64)

We must, therefore, allow that the moral law is a discovered relation to an object. As such, it not only determines the will a priori, but determines it to action. The moral law is a directive. In this it differs from the notion of ‘law’ considered speculatively, for in that usage ‘law’ does not determine to action. Indeed, this feature of the moral law is precisely what grounds it as moral. (Cf. IV, 401 n.)

If the achievement of the highest good were not contained within the intrinsic intelligibility of the moral law, such a law would cease to be ‘moral’ and would be only a speculative principle. In that case any discussion of the highest good would be required, as Professor Beck suggests, for reasons of systematic completeness only. Such, however, is not and need not be Kant's position.

⁹ Kroner maintains that Kant has replaced Metaphysics with Ethics. (op. cit. p. 10) This conclusion is based upon Kroner's conviction that Metaphysics is a speculative discipline. (Ibid. p. 67) In what follows we shall see that, since the object of Metaphysics is affirmed by practical reason, Metaphysics is a practical science. Thus, Kant did not replace Metaphysics, he reoriented it. Further, so long as interpreters of Kant insist—upon grounds extrinsic to the texts of Kant—that Metaphysics is speculative only, so long will they fail to understand this key feature in the unity of his thought.

¹⁰ The term “Glaube” here rendered as “belief” was translated as “faith” in the famous formula of B xxx: “I have therefore found it necessary to deny knowledge, in order to make room for faith.” In view of this we suggest that the term “faith” in this formula indicates a type of assent rather than the content of any proposition or set of propositions.

¹¹ The meaning of the term “philosophy” as it appears in this context is identical to the meaning of ‘Metaphysics’ as it has been used throughout this paper. (Cf. A 850: B 878)