Immanuel Kant's Critical Philosophy: Knowledge, Metaphysics, and Morality

Immanuel Kant: Convergence of Rationalism and Empiricism

Kant is a crossroads thinker in whom two streams converge: Modern Rationalism and Empiricism.

I. Approaching the Problem of Knowledge

• 1.1 Knowledge and the Subject: Transcendental Idealism
• 1.2 Metaphysics as a Science: Is it possible?
• 1.3 Limits of Knowledge: What can I know? (Principles and limits of knowledge). What are the conditions for the possibility of science?
• 1.4 Classification of Judgments: Which judgments advance science?
• 1.5 Apperception of Reality: The Phenomenon and the Noumenon.

II. Critique of Pure Reason

(Critical examination of the faculties of knowledge and the use of pure reason)

2.1 Transcendental Aesthetic

1. The Sensitivity (The First Faculty of Knowledge):
   • Matter of Knowledge: Sense impressions.
   • Form of Knowledge: Space and Time as "a priori forms of sensibility" and "pure intuitions."
2. Ability to make synthetic a priori judgments in Mathematics.

Classes of Judgments

• Analytical Judgments: Add nothing to the concept of the subject; reasoning is a priori and evident.
• Synthetic Judgments: The predicate adds qualities to the notion of the subject; reasoning is a posteriori.
• Scientific Knowledge: Requires universality and is constructed using synthetic a priori judgments.

2.2 Transcendental Analytic

1. The Understanding (The Second Faculty of Knowing and Judging): The judgments of understanding.
   • Matter of Knowledge: The Phenomenon (sense impressions + space + time).
   • Form of Knowledge: The transcendental Categories (a priori forms, pure concepts of understanding). These categories structure experience, allowing us to build synthetic a priori judgments in Physics, resulting in the object of knowledge.

2.4 Transcendental Dialectic

1. The Reason (The Third Faculty of Knowledge).
2. Impossibility of Metaphysics as a Science, because:
   1. Its purpose is the Noumena.
   2. Noumena cannot be captured by sensibility.
   3. Categories cannot be applied (leading to the Transcendental Illusion).
   4. Synthetic a priori judgments are not possible in this domain.
3. Critique of Metaphysics and the Unconditioned Ultimate Principles of Reason:
   1. The Paralogisms of the Ego (Soul).
   2. The Antinomies of the World (Cosmos).
   3. Failure of the demonstrations of the existence of God (Theological Idea).

III. Critique of Practical Reason and Groundwork of the Metaphysics of Morals

3.1 Criticism of Material Ethics

3.2 Moral Formalism

• The Concept of Duty.
• The Categorical Imperative.