A Commentary to Kant’s “Critique of Pure Reason”
Title: Kritik der Reinen Vernunft
The term critique or criticism, as employed by Kant, is of English origin. It appears in seventeenth and eighteenth century English, chiefly in adjectival form, as a literary and artistic term—for instance, in the works of Pope, who was Kant’s favourite English poet. Kant was the first to employ it in German, extending it from the field of aesthetics to that of general philosophy. A reference in Kant’s Logic64 to Home’s Elements of Criticism65 would seem to indicate that it was Home’s use of the term which suggested to him its wider employment. “Critique of pure reason,” in its primary meaning, signifies the passing of critical judgments upon pure reason. In this sense Kant speaks of his time as “the age of criticism (Zeitalter der Kritik).” Frequently, however, he takes the term more specifically as meaning a critical investigation leading to positive as well as to negative results. Occasionally, especially in the Dialectic, it also signifies a discipline applied to pure reason, limiting it within due bounds. The first appearance of the word in Kant’s writings is in 1765 in the Nachricht66 of his lectures for the winter term 1765-1766. Kant seldom employs the corresponding adjective, critical (kritisch). His usual substitute for it is the term transcendental.
Pure (rein) has here a very definite meaning. It is the absolutely a priori. Negatively it signifies that which is independent of experience. Positively it signifies that which originates from reason itself, and which is characterised by universality and necessity.67 By “pure reason” Kant therefore means reason in so far as it supplies out of itself, independently of experience, a priori elements that as such are characterised by universality and necessity.
Reason (Vernunft) is used in the Critique in three different meanings. In the above title it is employed in its widest sense, as the source of all a priori elements. It includes what is a priori in sensibility as well as in understanding (Verstand). In its narrowest sense it is distinct even from understanding, and signifies that faculty which renders the mind dissatisfied with its ordinary and scientific knowledge, and which leads it to demand a completeness and unconditionedness which can never be found in the empirical sphere. Understanding conditions science; reason generates metaphysic. Understanding has categories; reason has its Ideas. Thirdly, Kant frequently employs understanding and reason as synonymous terms, dividing the mind only into the two faculties, sensibility and spontaneity. Thus in A 1-2, understanding and reason are used promiscuously, and in place of reine Vernunft we find reiner Verstand. As already stated, the term reason, as employed in Kant’s title, ought properly to be taken in its widest sense. Sensibility falls within reason in virtue of the a priori forms which it contains. Kant does not himself, however, always interpret the title in this strict sense. The triple use of the term is an excellent example of the looseness and carelessness with which he employs even the most important and fundamental of his technical terms. Only the context can reveal the particular meaning to be assigned in each case.
The phrase “of pure reason” (der reinen Vernunft) has, as Vaihinger points out,68 a threefold ambiguity. (1) Sometimes it is a genitive objective. The critical enquiry is directed upon pure reason as its object. This corresponds to the view of the Critique as merely a treatise on method. (2) Sometimes it is a genitive subjective. The critical enquiry is undertaken by and executed through pure reason. This expresses the view of the Critique as itself a system of pure rational knowledge. (3) At other times it has a reflexive meaning. Pure reason is subject and object at once. It is both subject-matter and method or instrument. Through the Critique it attains to self-knowledge. The Critique is the critical examination of pure reason by itself. The first view would seem to be the original and primary meaning of the title. The second view very early took its place alongside it, and appears in many passages. The third view must be taken as representing Kant’s final interpretation of the title; it is on the whole the most adequate to the actual content and scope of the Critique. For the Critique is not merely a treatise on method; it is also a system of pure rational knowledge. It professes to establish, in an exhaustive and final manner, the a priori principles which determine the possibility, conditions, and limits of pure rational knowledge.69