Critique of Pure Reason

Nonfiction | Book | Adult | Published in 1781

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Summary

Chapter Summaries & Analyses

Prefaces and Introduction

Part I: “Transcendental Aesthetic”

Part II: “Transcendental Logic,” Book I, Chapter I

Part II: “Transcendental Logic,” Book I, Chapter II

Part II: “Transcendental Logic,” Book II, Chapters I-II

Part II: “Transcendental Logic,” Book II, Chapter III

Part II: “Transcendental Logic,” Division II, Books I-II, Chapter I

Part II: “Transcendental Logic,” Division II, Book II, Chapter II

Part II: “Transcendental Logic,” Division II, Book II, Chapter III

Transcendental Doctrine of the Method

Key Figures

Themes

Index of Terms

Important Quotes

Essay Topics

Themes

The Limits of Cognition

One of the main purposes of Kant’s Critique of Pure Reason is to set the boundaries of the extent of human cognition. This project is so valuable, according to Kant, because it will determine what can and cannot ever be known. Kant develops his theory of sensibility, understanding, and reason to articulate the various powers of cognition. Through our knowledge of what we are and how we experience, we can come to understand where we are prone to falter. This grants us the opportunity to recognize our weaknesses and refrain from endemic mistakes of natural reason.

Famously, Kant writes in the preface to the Critique that he “had to annul knowledge in order to make room for faith” (31). By striving to deduce what kind of knowledge is possible, and what is impossible, Kant believes that he “makes room for faith” by withdrawing the hubris to which reason is prone through its idle speculation. If the existence of God, the soul (and its immortality), and human freedom cannot ever be known for certainty, then these things must be taken on faith for the advancement of morality and the practical benefit of all humankind.

The Transcendental Condition

Among other things, Kant is famous for a new branch of philosophy called transcendental idealism. A basic method of this project requires finding the “transcendental conditions” for experience. In other words, Kant seeks the conditions for the possibility of experience. This includes various aspects of a general transcendental project: the transcendental aesthetic, the transcendental logic, the transcendental unity of apperception, etc. These correspond to a search for the conditions for the possibility of sensible experience, the conditions for the possibility of active understanding, and the conditions for the possibility of the experience of a conscious self. In each case, Kant seeks to avoid the pitfalls of rationalism and empiricism by sticking to a close investigation of the world as it must be constituted for our experience to be what it is.

For instance, during the early stages of the “Transcendental Logic,” Kant uses a process called transcendental deduction. He says that transcendental deduction refers to “in what way concepts can refer to objects a priori” (142). In other words, he seeks the necessary, essential structure of the mind that makes our concept of objects possible before any apprehension of actual objects. In empirical deduction, by contrast, Kant writes, “a concept has been acquired through experience and through reflection on experience, and which therefore concerns not the concept’s legitimacy but only the fact whereby we came to possess it” (142). A concept’s “legitimacy” can only be established transcendentally. The entire project of transcendental idealism is meant to elucidate an underlying structural reality of the mind that cannot be discovered through mere empirical observation, though it could be confirmed therein.

The Illusions of Reason

For Kant, reason is the highest and most honorable faculty of the human mind. It distinguishes humanity from the remainder of the animal kingdom, and it is that through which the possibility of morality and ultimate truth emerges. That said, reason is also prone to grave self-deceptions. As a result, peoples, religions, and philosophers have made serious mistakes throughout the millennia about the most important concerns of human speculation: the immortality of the soul, the freedom of the will, and the existence of God. Kant believes that through a critique of reason, i.e., an account of the limits of the capacity of reason, we can bring an end to these self-deceptions and the endless metaphysical conflicts that emerge from them.

The second half of the Critique deals with paralogisms, antinomies, and other illnesses and illusions to which reason is subject. In each of these cases, Kant shows that the claims of reason (to absolute knowledge of God, the soul, etc.) are unfounded. Reason’s ability to obtain foolproof theoretical knowledge of metaphysical reality is discovered to be severely limited, much more constrained than the illusions of reason (endemic to every human mind) would have one believe.

This does not mean that Kant disparaged of reason or its majesty. To the contrary, Kant thought that even though theoretical reason has significant limitations, the knowledge of these limitations opens the door to the advancement of practical reason. The pursuit of the ideal takes center stage, and Kant advocates for regulative ideas of God, freedom, systematic unity, etc. to guide human action toward the greatest possible good. We may not know God exists, but we should act as if God exists. We may not have direct awareness of the freedom of the will, but we should act as if we are all free.