Kant's Critique of Metaphysics and Theory of Knowledge

Kant's Critique of Traditional Metaphysics

Immanuel Kant critically examines the possibility or impossibility of metaphysics. He argues that the fundamental error of traditional metaphysics lies in attributing reality and existence to mere ideas. For Kant, metaphysics, understood as a set of judgments about reality beyond empirical experience, cannot be considered a science. Its inquiries extend beyond sensory perception, seeking to understand things-in-themselves (noumena) rather than just phenomena.

Traditional metaphysics often discusses the Soul, World, and God – concepts sometimes referred to as the three Cartesian substances. Kant asserts that we can never have direct intuition of any of these. Human reason, in its inherent tendency, seeks to understand the unconditioned, leading it to inquire about the Soul, the World, and God.

The Soul

Previous philosophical approaches to the Soul often led to paradoxes. Kant's critique of the Soul addresses these, particularly in relation to rational psychology.

The World: Kant's Antinomies

When considering the World as a thing-in-itself, reason encounters contradictory statements, which Kant termed antinomies. These antinomies reveal the limits of pure reason when applied beyond experience.

Types of Antinomies:

• Mathematical Antinomies: These relate to the idea of the world's phenomena, particularly concerning concepts like time and space (e.g., whether the world has a beginning in time and is limited in space).
• Dynamical Antinomies: These concern the idea of a complete set of causes within the world (e.g., freedom versus natural causality, or the existence of a necessary being).

God: The Ideal of Pure Reason

The concept of God arises from reason's tendency to unify all experience into a single, ultimate principle. Traditional arguments for God's existence often posit a necessary being. However, for Kant, existence is an a priori concept, a category of understanding used to organize sensory data. If the existence of God were to be established, it would require a posteriori knowledge – that is, sensory data ordered by the category of existence. Since we have no sensory data corresponding to God, the category of existence cannot legitimately be applied to God. This highlights the limitations of speculative reason in proving God's existence.

Kant's Theory of Knowledge

Kant's theory of knowledge, or cognition, posits that two fundamental faculties are necessary for human understanding:

• Sensibility: Studied in the Transcendental Aesthetic.
• Understanding: Examined in the Transcendental Analytic.

Transcendental Aesthetic: The Science of Sensibility

The Transcendental Aesthetic investigates sensibility, which is humanity's capacity to be affected by sensations. Empirical insights, such as perceiving color or meaning, are inherently sensitive. To have these intuitions, we require a priori forms of sensibility, which are transcendental conditions for all intuition. The raw data of experience, organized by these forms, are called phenomena.

Kant identifies Space and Time as the two pure intuitions, or a priori forms of sensibility. They are not concepts derived from experience but are the very conditions under which any experience is possible.

For the representation of any object, Kant notes that two conditions must apply:

• Material Condition: The sensory data itself.
• Formal Condition: The a priori forms (Space and Time) that enable the organization and structuring of this data.

The Transcendental Aesthetic is crucial for understanding mathematical knowledge, as geometry relies on the pure intuition of space, and arithmetic relies on the pure intuition of time.

Space, Time, and Mathematical Judgments

Traditional geometry, for instance, relies on the universal and necessary conditions for spatial representations. Without the pure intuitions of space and time, neither geometry nor arithmetic would be possible. Kant concludes that mathematics consists of synthetic a priori judgments because space and time, as pure intuitions, provide the synthetic element (extending our knowledge) while being a priori (independent of experience).

Transcendental Analytic: The Science of Understanding

The Transcendental Analytic focuses on the understanding, which is the faculty that sorts sensible intuitions according to rules, using categories. Categories are pure concepts of the understanding, not derived from experience, but rather the conditions for any coherent thought about objects.

To gain knowledge, we must make judgments. To formulate these judgments, we require categories. Kant argues that there are as many categories as there are possible forms of judgment, which he systematically derives in his table of categories.