Immanuel Kant’s Critique of Pure Reason: Limits of Knowledge
Historical Context
Immanuel Kant belongs to the period of modern philosophy, particularly the Enlightenment. Influenced by the rationalist and empiricist ideas about knowledge, he exceeded both positions with his own original philosophy: transcendental idealism. Furthermore, he represented an achievement in moral philosophy by proposing a novel formal ethics characterized by the defense of human dignity above all else.
Central Theme
Kant argues that it is impossible to apply the theoretical use of reason beyond the limits of experience because it would encroach on land not within the scope of its own practical reason.
Key Ideas
- The Critique of Pure Reason has a negative utility: a warning that we can never go beyond the limits of experience with the theoretical use of reason.
- The principles that theoretical reason uses beyond its own boundaries have resulted in a reduction in the use of reason.
- These principles are intended to extend the limits of sensitivity (which can only be applied) and even suppress practical reason.
- Pure reason has a necessary practical use whose scope of action goes beyond the limits of experience.
Summary of Ideas
The main thesis of the text is at the beginning, where Kant claims that the Critique of Pure Reason tells us that the limits of the theoretical use of reason are in experience. The premises on which he relies to support this are, firstly, that the principles with which speculative reason goes beyond the limits of experience show not an extension but a reduction in the use of our reason. The sample of what he just said will appear in the premise which states that these principles threaten to extend the limits of sensitivity and suppress practical reason. Finally, the text concludes by noting that what is stated in the ideas presented above will be more clearly recognized if a second application of the compelling reason to go beyond experience is considered: the practical use of reason, moreover, is absolutely necessary.
Explanation of Kant’s Masterpiece
The Critique of Pure Reason is the masterpiece of Immanuel Kant. A symbol of criticism and overcoming Kantian rationalist and empiricist views of knowledge, this work has as its objective the analysis of the limits of rational knowledge of reality. Indeed, Kant, noting the huge growth experienced by modern science since Galileo’s time, led him to wonder why metaphysics was stagnant and mired in endless digressions that did not lead anywhere. The issue of metaphysics and the task that should be clarified, therefore, would be to find out what conditions mathematics and physics share to say about them that they are science and see if the same is met with respect to metaphysics.
This text, therefore, presents the fundamental thesis of the Kantian theory of knowledge and is based on a draft analysis of the rational faculty. For Kant, knowledge has limits, given by experience, whether external or internal, beyond which no knowledge can obtain a scientific kind. Scientific and not moral, because as is seen in the text, Kant differentiates between two uses of the same faculty: reason. Thus, our philosopher distinguishes between a theoretical and a practical dimension of reason. To the theoretical use of Kant belongs the realm of being and, therefore, scientific knowledge of reality.
The analysis in this field led him to conclude that we can only know phenomena theoretically and, therefore, in this dimension, as stated in the text, reason has limits. Sensory experience, which Kant called the field of knowledge, would be determined by a series of conditions a priori that Kant classified as a priori forms of sensibility (space and time) and pure concepts of understanding (categories). Thus, knowledge begins with experience, but not everything depends on it. This is where Kant, against all previous theories of knowledge, claims that it is not the object that sets the conditions of knowledge, but it will be the subject (turnabout). When we know, we do not grasp the object as it is, but in knowing we transform it, adapting it to a priori conditions that transcend the subject to apply the material of experience.
But these a priori conditions or, as stated in the text, these principles of speculative reason with which we try to exceed the limits of experience, do not represent an expansion but a reduction in the use of reason. Both the a priori forms of sensibility and the categories can only apply to material that experience provides; therefore, they do not produce knowledge by themselves, as a rationalist would assert. If these principles venture beyond their limits in the subject, they will only produce the illusion of true knowledge, when what they really are would be errors produced by mistake. For that reason, and as stated at the end of the fragment, it is necessary to note that in addition to the theoretical use, there is a practical use of reason that is absolutely necessary. The practical use of reason, as the text extends, goes beyond the limits of experience, turning metaphysical concepts into the conditions of possibility of morality. Thus, human freedom, the immortality of the soul, and the idea of God as a symbol of the supreme good are the postulates of practical reason on which, on the other hand, it is possible to obtain better knowledge. These assumptions are not phenomena but noumena on which you can only have faith, but, yes, a rational faith. It is hope, not knowledge, but always a hope based on rational arguments.