康德是啟蒙理性思想的重要代表，在啟蒙運動史上佔據著獨特的地位。這不僅在於他自覺地繼承了啟蒙運動的遺產並將理性至上的原則發揚光大，而且在於他對啟蒙理性作了兩點極為重要的改造。這兩點改造都體現在對理性運用的限制上，第一點是理性運用被區分為「公開運用」和「私自運用」，後一種運用受到相對的限制；第二點是理性被區分為理論理性和實踐理性，對前者的運用受到兩個方面的絕對限制即絕對禁止理性與感性對象發生關係、絕對禁止純粹知性原理的先驗運用。康德對理性運用的這些改造看似新穎深刻，可是卻蘊含著內在的矛盾。從胡塞爾的先驗現象學視角，我們可以看出這種矛盾的癥結源於康德對感性和知性的僵硬區分以及對理論理性和實踐理性的人為割裂。

Kant is a very important representative of the idea of reason of the Enlightenment and holds a special position in the movement of Enlightenment. This is not only due to the fact that he has taken over the heritage of the Enlightenment in a conscious way, but also that he has made two extremely significant transformations of it, which lie in the limitations of the application of reason, that is, firstly, the application of reason is divided into ＂public application＂ and ＂private application＂, among which the latter undergoes a relative restriction; secondly, theoretical reason is distinguished from practical one, among which the former’s application undergoes a restriction in two aspects: Absolutely restricting a direct relationship between reason and aesthetic object on the one hand, absolutely restricting the transcendental application of pure principles of understanding on the other hand. It seems that Kant’s reform of the applications of reason is very deep and initial, but in fact it contains internal contradictions. From Husserl’s perspective of transcendental phenomenology we could find out that the problematic of these contradictions originates from Kant’s rigid differentiation between sensibility and understanding and his artificial separation of the theoretical reason from the practical one.