Kant's Dialectic

The discussion of Kant's metaphysics and epistemology so far (including the Analytic of Principles)has been confined primarily to the section of the Critique of Pure Reason that Kant calls the Transcendental Analytic. The purpose of the Analytic, we are told, is "the rarely attempted dissection of the power of the understanding itself." (A 65/B 90). Kant's project has been to develop the full argument for his theory about the mind's contribution to knowledge of the world. Once that theory is in place, we are in a position to see the errors that are caused by transgressions of the boundaries to knowledge established by Kant's transcendental idealism and empirical realism. Kant calls judgments that pretend to have knowledge beyond these boundaries and that even require us to tear down the limits that he has placed on knowledge, transcendent judgments. The Transcendental Dialectic section of the book is devoted to uncovering the illusion of knowledge created by transcendent judgments and explaining why the temptation to believe them persists. Kant argues that the proper functioning of the faculties of sensibility and the understanding combine to draw reason, or the cognitive power of inference, inexorably into mistakes. The faculty of reason naturally seeks the highest ground of unconditional unity. It seeks to unify and subsume all particular experiences under higher and higher principles of knowledge. But sensibility cannot by its nature provide the intuitions that would make knowledge of the highest principles and of things as they are in themselves possible. Nevertheless, reason, in its function as the faculty of inference, inevitably draws conclusions about what lies beyond the boundaries of sensibility. The unfolding of this conflict between the faculties reveals more about the mind's relationship to the world it seeks to know and the possibility of a science of metaphysics.

Kant believes that Aristotle's logic of the syllogism captures the logic employed by reason. The resulting mistakes from the inevitable conflict between sensibility and reason reflect the logic of Aristotle's syllogism. Corresponding to the three basic kinds of syllogism are three dialectic mistakes or illusions of transcendent knowledge that cannot be real. Kant's discussion of these three classes of mistakes are contained in the Paralogisms, the Antinomies, and the Ideals of Reason. The Dialectic explains the illusions of reason in these sections. But since the illusions arise from the structure of our faculties, they will not cease to have their influence on our minds any more than we can prevent the moon from seeming larger when it is on the horizon than when it is overhead. (A 297/B 354).

In the Paralogisms, Kant argues that a failure to recognize the difference between appearances and things in themselves, particularly in the case of the introspected self, lead us into transcendent error. Kant argues against several conclusions encouraged by Descartes and the rational psychologists, who believed they could build human knowledge from the "I think" of the cogito argument. From the "I think" of self-awareness we can infer, they maintain, that the self or soul is 1) simple, 2) immaterial, 3) an identical substance and 4) that we perceive it directly, in contrast to external objects whose existence is merely possible. That is, the rational psychologists claimed to have knowledge of the self as transcendentally real. Kant believes that it is impossible to demonstrate any of these four claims, and that the mistaken claims to knowledge stem from a failure to see the real nature of our apprehension of the "I." Reason cannot fail to apply the categories to its judgments of the self, and that application gives rise to these four conclusions about the self that correspond roughly to the four headings in the table of categories. But to take the self as an object of knowledge here is to pretend to have knowledge of the self as it is in itself, not as it appears to us. Our representation of the "I" itself is empty. It is subject to the condition of inner sense, time, but not the condition of outer sense, space, so it cannot be a proper object of knowledge. It can be thought through concepts, but without the commensurate spatial and temporal intuitions, it cannot be known. Each of the four paralogisms explains the categorical structure of reason that led the rational psychologists to mistake the self as it appears to us for the self as it is in itself.

We have already mentioned the Antinomies, in which Kant analyzes the methodological problems of the Rationalist project. Kant sees the Antinomies as