Abstract

In the "Transcendental Aesthetic" section of the Kritik der reinen Vernunft Kant dismisses both the Newtonian and the Leibnizian notions of space. In their place he offers his own view that space is a "pure intuition" which is both empirically real and transcendentally ideal. Kant means by this that space is objectively valid and is applicable to things as they appear to us, but that it is not something that either exists independently of humans or as a relation that pertains between things as they really are. In his claim that space is valid only for appearances, Kant rules out the possibility that space is both subjective and objective . Whether Kant is entitled to rule out this possibility has been a perennial topic for debate among Kantian scholars. Critics argue that on his own principles Kant has no justification for dismissing die Dritte Moglichkeit, the possibility that space applies both to appearances and to die Dingen an sich. The question of die Dritte Moglichkeit was taken up earnestly in the middle of the nineteenth century when F. A. Trendelenburg charged that Kant had not considered this possibility. Kuno Fischer attempted to defend Kant, and with that a controversy began that would last almost fifty years and that would draw into it many prominent Neo-Kantian scholars. Some participating in the controversy believed that Trendelenburg overstated the case and argued that Kant, in fact, had considered die Dritte Moglichkeit. The question was not whether he considered it but whether he was entitled to dismiss it. Arnoldt, Cohen, Grapengiesser and others claimed that he was entitled to do so, while Tiebe and Vaihinger, among others, charged that he was not. ;I trace this controversy over the Kantian conception of space from its beginning between Trendelenburg and Fischer to its effective conclusion. I then sketch a possible defense for Kant. I hope to have shed some light on Kant's controversial conception of space by examining it in reference to an important controversy among members of the German academic community