Kant’s Philosophical Evolution and the Critical System

Background: Immanuel Kant made contact with the work of Isaac Newton during the first stage of his career. Newton had succeeded in completing the scientific Revolution of sixteenth and seventeenth-century physics. For Kant, this served as the model par excellence of scientific knowledge—the kind of knowledge discussed in the Critique of Pure Reason.

The Influence of Christian Wolff

The dominant figure in German philosophy during the first half of the eighteenth century was Christian Wolff. His thought represented an extreme rationalism where philosophy was conceived as a deductive science. In this framework, philosophy can prove everything besides the first logical principles, and the role of experience is nil.

The Structure of Wolffian Metaphysics

Wolff's metaphysics divides into two groups:

• General Metaphysics: Deals with the theory of being (ontology).
• Special Metaphysics: Deals with the soul (rational psychology), the theory of the world (rational cosmology), and the theory of God (rational theology).

Kant’s Departure from Pure Rationalism

Kant began his career as a rationalist in this style, but soon deviated from the method. Kant insisted that proceeding by pure concepts alone cannot provide the existence of anything. While mathematics can proceed deductively because it exists beyond the material existence of its objects, in contrast, metaphysics and physics cannot proceed in the same way because they deal with existing things.

In a work from 1765, he considered the school of metaphysical systems of rationalism as "dreams of reason." He anticipated that a procedure of reason leading beyond the limits of experience belongs to the very nature of reason itself; however, it is apparently not true knowledge.

The Impact of Hume and the Birth of Idealism

With this view, contrary to traditional metaphysics, Kant had to enter into dialogue with the empiricists, as they were the ones who had gone furthest in criticizing the possibilities of reason. Reading David Hume was very important for Kant to overcome his radical rationalism. Kant concluded skeptically regarding the possibility of metaphysics as a science, but not in regard to physics. Otherwise, the direct influence of Hume on Kant remained specific.

In summary, Kant experienced two major philosophical influences: rationalism and empiricism. In his pre-critical stage, Kant was a rationalist. Later, the study of Hume's work led him to critically consider that rationalism. This was the origin of Kant's critical system, which is the "third way" tried by Kant. It avoids both rationalism (which falls into dogmatism by pretending to grasp the reality of ideas) and empiricism (which falls into skepticism by claiming that ideas originate only from experience), resulting instead in Idealism.