Immanuel Kant’s Theory of Knowledge: A Synthesis of Rationalism and Empiricism
Philosophical Framework
In 18th-century Europe, thought was diverse. While some noted a shared mentality aligned with Enlightenment values, philosophy saw the decline of classical metaphysical approaches. A strong focus on human problems emerged, particularly in epistemology (theory of knowledge). Political and ethical issues were also important, with Rousseau’s concept of general will influencing Kant’s deontological ethics. Enlightenment philosophers shifted from Descartes’ rationalist method to Newton’s experimental model based on observation. Kant attempted to reconcile Newtonian physics with Hume’s critique of causality and induction. He integrated aspects of rationalism and empiricism, stating, “All our knowledge begins with experience, but not everything comes from experience.” This acknowledges the role of experience while emphasizing the subject’s contribution.
Immanuel Kant: The Theory of Knowledge
Kant’s philosophy epitomizes the Enlightenment, captured by the motto “sapere aude” (dare to know). In “What is Enlightenment?” Kant argued that humans live in an intellectual “minority,” guided by others. True intellectual maturity is achieved through autonomous thought. Kant identified three ages of reason:
- Dogmatic Age: The infancy of reason.
- Skeptical Age: Reason is “chastened” by experience.
- Critical Age: Mature reason, engaging in self-critique.
Kant distinguished between specialized philosophy and cosmopolitan philosophy, the latter concerning everyone. Cosmopolitan philosophy addresses four questions:
- What can I know? (Epistemology, addressed in Critique of Pure Reason)
- What should I do? (Ethics, addressed in Critique of Practical Reason)
- What can I hope for? (Aesthetics and religion, addressed in Critique of Judgment)
- What is man? (Answered by addressing the previous three questions.)
This document focuses on the first question: What can I know?
The Problem Statement
Kant synthesized rationalism and empiricism. Initially a rationalist, he was influenced by Hume, stating, “Hume awakened me from my dogmatic slumber.” He agreed that experience is the origin and limit of knowledge (empiricism), but the conditions of possibility reside in the subject a priori (rationalism). These conditions, unlike innate ideas, apply only to experience. Kant challenged the naive view that the subject is a mere receiver of knowledge. In the preface to Critique of Pure Reason, he introduced his “Copernican revolution”: knowledge depends not on the object (reality) but on how the subject knows it. Kant investigated the conditions for scientific knowledge, focusing on judgments or propositions. He classified judgments based on linguistic and epistemological criteria:
- Linguistic:
- Analytic Judgments: The predicate is contained in the subject, adding no new knowledge (tautologies, necessary, and universal).
- Synthetic Judgments: The predicate is not contained in the subject, providing new information (ampliative).
- Epistemological:
- A Priori Judgments: Independent of experience.
- A Posteriori Judgments: Dependent on experience.
Kant argued that scientific judgments are synthetic a priori, expanding knowledge while being universal and necessary.
The Critique of Pure Reason
Kant identified two sources of knowledge: sensibility (intuitions) and understanding (concepts). “Intuitions without concepts are blind, concepts without intuitions are empty.” Knowledge arises from the cooperation of these faculties. The subject receives intuitions from experience and spontaneously creates a priori concepts to give meaning and unity to intuitions. Critique of Pure Reason examines the faculties of reason (sensibility, understanding, and reason) and the conditions for mathematics, physics, and metaphysics, respectively.
Transcendental Aesthetic
This section examines sensibility, the passive faculty receiving impressions. The conditions of possibility for sensibility are space and time, which are pure a priori intuitions. They precede experience and serve as coordinates for it. Kant further explores the possibilities of mathematics, establishing space as the condition for geometry (spatial qualities of bodies) and time as the condition for arithmetic (temporal succession).