Kant's Critical Philosophy: Knowledge, Morality, and Reason

Kant's Philosophical Evolution

From Pre-Critical Metaphysics to Critical Inquiry

During the pre-critical period, Kant's metaphysics was considered a science capable of knowing transcendent objects located beyond all possible experience (such as noumena, God, soul, and the world as a whole). By 1765, after reading David Hume, Kant began to doubt whether metaphysics truly constituted scientific knowledge.

The intense reflection on the problem of metaphysics made Kant aware that a theory of knowledge must begin with a critique to ascertain the capabilities and limits of reason.

The Critique of Pure Reason: Core Questions

In Critique of Pure Reason (1781), the work that opens the critical period of his thought, Kant discusses the use of theoretical reason (its possibilities and limits for scientific knowledge). In the preface to the second edition, he raises three fundamental ideas:

• How to secure the path of science?
• How to understand the use of reason beyond all experience?
• How to reconcile science and morality?

Kant's Copernican Revolution in Metaphysics

This prologue is an accurate summary of the main thesis of Kant's transcendental idealism.

In the foreword, Kant states that while mathematics and physics securely advance, metaphysics remains stagnant because it has not carried out a revolution in its perspective, echoing these sciences. This revolution involves constructing their respective objects of study a priori, either through a priori forms of sensibility (as in mathematics) or a priori concepts of understanding (as in physics).

Transcendental Idealism: Limits and Moral Scope

Kant maintains that metaphysics failed to recognize that it is the objects that determine our knowledge. Instead, it is correct to assume that our mind, through a series of a priori concepts independent of experience, structures and organizes the known object.

This interpretation of knowledge has a negative result because it limits our knowledge to phenomena and excludes the noumena, or things-in-themselves (such as immortality, soul, and God), which cannot be studied without reason falling into contradiction with itself. Thus, Kant famously states, "I had to abandon knowledge to make room for faith."

However, there is also a positive side, since such ideas may have a legitimate use in the moral field. Reason is a single faculty, but it has two different applications: theoretical and practical (moral).

Bridging Rationalism and Empiricism

This work addresses the dogmatism of rationalists, who think they can know the supersensible, while also reducing the claims of empiricist skepticism, which denies its existence. Kant shows that metaphysical concepts play an important role not only in the field of knowledge but also at the level of morality, supporting a rational faith whose validity is one of humanity's major concerns.