EXTENSION

[A22/B37] Kant speaks of the extension of a concept, in roughly the normal sense, and also of spatial things as having extension. Of the latter, he writes "by means of outer sense, a property of our mind, we represent to ourselves objects as outside us, and all without exception in space. In space their shape, magnitude, and relation to one another are determined or determinable". [A26/B42] A conclusion of the Aesthetic is that things in themselves have no extension (are not in space), namely because space, as a pure intuition, is a form of sensibility. [A2/B6] In the Introduction, he argues that not only do we know a priori that all objects are extended, but indeed that extension "has its seat in our faculty of a priori knowledge".