Kant's Three Conceptions of Infinite Space

Kant's treatment of infinity seems to be plagued by two contradictions. First, the Transcendental Aesthetic claims that space is an infinite given magnitude, whereas the First Antinomy argues that the spatial world cannot be infinite. Second, the Transcendental Aesthetic claims that the representation of infinite space belongs to sensibility, but the third Critique seems to argue, instead, that infinity is an Idea of reason. This paper resolves these apparent contradictions by noting that Kant groups his various conceptions of space into three kinds: (1) merely subjectively given space, (2) objectively given space, and (3) objective space as a mere Idea. Attending to these three conceptions of space illustrates that the Transcendental Aesthetic, First Antinomy, and third Critique refer to different conceptions of infinite space and thus do not contradict one another, illuminating the importance of Kant's various conceptions of space for his critical project.