Kant’s Theory of Knowledge: Judgments, Categories, and Metaphysics
Classification of Judgments and Theory of Knowledge
Because science is a system of trials, we can ask: what conditions make scientific judgments possible? Kant presents two classifications of judgments:
1. Judgments are divided into analytical and synthetic:
- Analytical judgments: The predicate is included in the subject; analyzing the subject concept suffices, providing no new information. They are not extensive.
- Synthetic judgments: The predicate is not included in the subject; they are informative, extensive, and expand our knowledge.
2. Judgments are classified by how their truth is known: a priori or a posteriori:
- A priori judgments: Their truth is known independently of experience; they are universal and necessary.
- A posteriori judgments: Their truth is known from experience; they are contingent.
The most important scientific judgments are synthetic a priori: they are informative (synthetic) yet universal and necessary (a priori), not derived from experience. Fundamental principles of mathematics and physics are of this type.
Transcendental Aesthetic
Transcendental Aesthetic is the science of the principles of sensitivity, the ability to have feelings. It explains the conditions for sensory knowledge. Kant distinguishes two elements in perception: matter and form.
- Matter: Sensations, which are a posteriori and given.
- Form: The way sensations are ordered, which is a priori, existing in the mind as pure forms of intuition (space and time).
Synthesis (union) of raw empirical data forms the phenomenon. The a priori principles or pure forms of sensibility are space and time. They are conditions for all experience, not objective properties of things themselves, but ways we experience external and internal phenomena. Mathematics (geometry and arithmetic) is based on these a priori forms.
Transcendental Analytic
Sensitivity provides a unified synthesis of sensations in space and time, but understanding is needed to comprehend objects. Understanding refers phenomena to concepts. Kant distinguishes between empirical concepts (from experience, a posteriori) and pure concepts or categories (a priori), such as substance, causality, possibility, and unity. These categories are not derived from experience but structure our understanding.
Knowledge arises from the application of categories to the multiplicity given in sensation. Categories are transcendental conditions; we cannot think about phenomena without applying them. Knowledge is the cooperation between sensitivity (providing objects) and understanding (providing thought). Categories apply only to phenomena (sensible impressions in space and time), not to things beyond experience. Dogmatic philosophy errs by using categories for transempirical realities (God, the soul). Physics can know a priori that the world has a mathematical structure and that categories have empirical validity because phenomena are structured according to categories. Kant’s philosophy legitimizes the Newtonian universe.
Transcendental Dialectic
Transcendental Dialectic examines whether metaphysics can be a priori knowledge, concluding that it is impossible as a discipline. Metaphysics deals with transcendent objects (soul, freedom, immortality, God, the world as a whole), but science necessarily uses categories, which are only legitimately applied to phenomena. Reason seeks increasingly general judgments, aspiring to the unconditional. When reason goes beyond experience, it leads to contradictions. Science progresses by extending reason, but this trend inevitably leads to metaphysical theories about the soul, God, and the world.
Reason has three ideas: God, soul, and world. These lack empirical referents but have a regulatory use, guiding research and the quest for deeper explanations.
Formal Ethics
Kant rejects hypothetical imperatives (like eudaemonism) because they are selfish. He proposes the categorical imperative: act only according to that maxim whereby you can at the same time will that it should become a universal law. Moral action is an end in itself, based on the dignity of individuals, never a means to an end. This is autonomous morality, based on universal principles from human nature itself. It is a formal ethic, prescribing not specific actions but the form of the imperative. It is a moral duty based not on what I do but on how I do it.
Kant justifies his ethical principles with metaphysical postulates of practical reason: freedom (action is conditioned by our nature), immortality of the soul (allowing for eternal moral progress), and God (ensuring ethical behavior leads to happiness, as moral actions may not have evident effects in this world).