Is Space The Form Of Intuition Or The Form Of Thing In Itself?

The debate between Trendelenburg and Fischer in the 19th century is a persistent debate about the nature of space in Kant’s philosophy.The core of the debate was whether Kant recognized space as both a priori intuitive form of cognitive subjects and a form of the thing in itself.Trendelenburg argued that Kant only considered two possibilities,one of which is that space is merely a subjective form of the subject and the other is that space is merely an objective form of the thing itself,but there is a third possibility that space can be both a subjective and an objective form,both ideal and real.Trendelenburg thought that Kant ignored the nature of the space in a third possibility of consideration.This kind of philosophy,which does not regard space as both the form of intuition and the form of things in themselves,will lead to the difficulty of skepticism and fail to explain the origin of the infinite concept of space in our minds.To this end,Trendelenburg proposed his own metaphysics of motion as an alternative solution to the above problem.Fischer explains the argument and core point of Kant’s transcendental idealism,and thinks that Kant has ruled out the possibility of space as both the form of intuition and the form of things in themselves.In addition,some other Kantians defend Kant from different perspectives,such as transcendental dimension,the distinction between phenomena and the thing in itself,external semantics,and the distinction between strong and weak versions of transcendental idealism.This paper will mainly base on the original literature of Trendelenburg and Fischer,combined with their most direct statements in this debate,to restore the core thesis and argument of their debate.Finally,after summarizing the debate,this paper will point out that the core of the controversy lies in the different understandings and interpretations on what is the difference between the concept appearance and thing in itself.This paper will further propose that the contrast between the development of contemporary metaphysical theory and the position of the dispute between the two of them may serve as a possible theoretical extension perspective to provide some new possibilities for the study of this debate.