Understanding Kant: Critique of Pure Reason, Stages of Reason, and Metaphysics
Contextualizing Kant
Kant’s philosophical work is broadly categorized into three areas:
Critique of Pure Reason
Immanuel Kant first published his seminal work, Critique of Pure Reason, in 1781. Initially, the work did not meet the public or critical acclaim Kant anticipated, sparking considerable debate in philosophical circles. Kant attributed this lukewarm reception to misinterpretations and the complexity of the text. He subsequently wrote Prolegomena to Any Future Metaphysics That Will Be Able to Come Forward as Science to clarify his ideas. The second edition of Critique of Pure Reason contained no substantial changes but aimed to facilitate reader understanding, particularly regarding transcendental idealism.
Kant’s intellectual journey can be divided into two periods. His writings before 1770 are considered pre-critical, during which he explored various topics and attained a full professorship. This was followed by an 11-year period of silence dedicated to contemplation. The second phase began in 1781 with the publication of Critique of Pure Reason. Other significant works include Critique of Judgment and Perpetual Peace.
Stages of Reason
Kant proposed that human reason progresses through three stages:
- Dogmatic Stage: This initial stage, akin to a childlike state of reason, aligns with 17th and 18th-century rationalism. Rationalists believed in an innate intellectual capacity through which reason could operate independently. They considered reason the primary source of knowledge. Kant, however, posited that knowledge arises from the collaboration of sensibility and understanding.
- Skeptical Stage: Here, reason critically examines its own products, mirroring the empiricism of the 17th and 18th centuries, which emphasized sensory experience as the foundation of knowledge. Empiricism strongly opposed rationalist ideals. Kant credited Hume’s philosophy with awakening him from his “dogmatic slumber.” Hume’s limitation of human knowledge to experience challenged the validity of universal and necessary concepts.
- Critical Stage: Reason transcends skepticism and enters a critical phase. This stage involves examining reason’s capabilities and limitations. Kant’s philosophical system exemplifies this critical approach.
Kant in the History of Philosophy
Metaphysics and Science
Kant defined metaphysics in two ways: as an innate human disposition to contemplate rationally beyond experience (e.g., the immortality of the soul and God) and as a science. Traditional metaphysics, in Kant’s view, had failed to adequately address these fundamental questions. He proposed a new understanding of metaphysics as a “Critique of Knowledge,” refining traditional dogmatic metaphysics through critical analysis. This shift, inspired by methodological revolutions in mathematics and physics, involved a “Copernican turn” in perspective. Kant argued that individuals should not passively receive knowledge from nature but actively engage with it, much like a judge questioning a witness, evaluating evidence based on their own criteria and knowledge.
This perspective fundamentally altered the understanding of knowledge. Instead of the individual conforming to the object, objects now depend on the subject’s cognitive structures. Mathematics is considered a science due to the a priori forms of sensibility (space and time), which are pure intuitions. Physics is the science of pure concepts (categories) of understanding. Traditional metaphysics, however, is not a science because it claims knowledge beyond the realm of experience. Knowledge, according to Kant, results from the interaction between particular and contingent sensory data and the universal and necessary structures provided by the subject (space, time, categories).
Philosophical tradition distinguished between two types of judgments: analytic and synthetic. Analytic judgments are truths of reason, where the predicate is already contained within the subject (e.g., “All bachelors are unmarried”). They are necessarily true but do not expand knowledge. Synthetic judgments are truths of fact, providing new information but lacking universality and necessity (e.g., “The table is brown”). Kant argued that neither type alone could form the basis of science, which requires both necessity/universality and the expansion of knowledge. He proposed a third type of judgment: synthetic a priori judgments, which are both informative and universally necessary, derived from the structure of experience itself.