Journal of the History of Philosophy

Kant’s Thinker is an excellent and important addition to the literature. In it, Patricia Kitcher aims at arriving at a comprehensive understanding of Kant’s theory of the cognitive subject. To this end, she analyzes a central component of the most notoriously difficult part of the Critique of Pure Reason, the theory of the unity of apperception in the chapter on the Transcendental Deduction of the Categories. In Kitcher’s view, the ultimate payoff of such a study is that Kant’s theory can “provide a ‘new’ source of illumination for current attempts to understand the nature of cognition and the mind” (3). This may be so. But the main value of the book will likely be for Kant scholars, who will appreciate the depth and sophistication of her interpretation.

The book is divided into three parts—background, theory, and evaluation—and fifteen chapters. After a brief overview chapter, Kitcher devotes five chapters to the history of the problem of the cognitive subject that is essential to understanding Kant’s problems and concerns in the Critique of Pure Reason. The chapters concern Locke’s theory of inner sense (ch. 2), theories of personal identity in Locke, Leibniz, Hume, and Tetens (ch. 3), rationalist metaphysics of the mind (ch. 4), eighteenth-century theories of consciousness and self-consciousness (ch. 5), and Kant’s reflections in the 1770s on the nature of apperception (ch. 6). This material is all handled nicely, and Kitcher makes clear the complicated philosophical route that Kant navigates in the Critique.

The central chapters (7–11) are devoted to Kitcher’s interpretation of Kant’s account of the transcendental unity of apperception. The argument here is complex and subtle, and Kitcher does an excellent job of setting her view against the many rival interpretations in the literature. (unfortunately, given the confines of this review, I cannot describe the ways that Kitcher is setting her views against those of others.) The driving question of the Critique of Pure Reason is “how subjective conditions of thinking should have objective validity” [End Page 502] (A 89/B 122). And the answer is, of course, that there are certain pure concepts that originate in the understanding and that make empirical cognition possible. But in empirical cognition, there is also an act of synthesis, which is necessary for a number of reasons. First, since Kant accepts the Leibnizian notion of petites perceptions, he must explain how they can be joined to produce a conscious image. Second, since Kant denies that temporal relations can be sensed, he must show that the representation of a succession of states is produced somehow by combining representations. Third, any attempt to subsume intuitions under concepts, that is, to make a judgment, likewise requires the synthesis of representations. Fourth, Kant believes that cognition requires that sensory data be arranged into suitable intuitions for categorial templates, something described by his synthesis speciosa. Finally, the nub of the entire problem: in order for something to be an object of cognition, it must relate to a possible consciousness; there must be a unity of apperception. Put differently, what the Transcendental Deduction is to show is the truth of the “I-think doctrine,” the doctrine that “The I think . . . [accompanies] all my representations” (B 132). The important upshot of this view, for Kant and for Kitcher, is that “the key to understanding how representations can refer to an object are the conditions required for a unity of consciousness” (131). The power of apperception thus combines representations, bringing about both cognition and the unity of apperception. But there is an anti-metaphysical consequence to Kant’s view: this power cannot be known to endure in or be a metaphysical disposition of a substance. One of Kitcher’s complaints is that, while the Transcendental Deduction shows the necessity of the “I-think” in cognizing objects, “it does not work out a good theory of how cognizers are able to use the representation ‘I’” (160). But this is just part and parcel of his critique of rational psychology; for...