Human Spontaneity and the Natural Order (Critique of Pure Reason)
Kant transformed the landscape of philosophy by introducing his theory of transcendental idealism. His theory addresses the problems raised by both rationalists and empiricists about the relationship between knowledge and the object of knowledge, or, how do we have necessary and universal knowledge about the external world if all we can think of is our ideas. Rationalists starts with innate ideas (concept) and tries to derive knowledge with the ideas and make judgments about things even outside of empirical realm, like the immortality of the soul and existence of God. Empiricists starts with sense perceptions (intuition), and claims that the knowledge is abstracted from the sense perceptions, however, it cannot address Hume’s doubt that causality is just our mental habit and bears no real significance in the real world.