Full Idea
We have no insight into the possibility of noumena (things in themselves), and the domain outside the sphere of appearances is empty (for us).
Gist of Idea
We cannot know things in themselves, but are confined to appearances
Source
Immanuel Kant (Critique of Pure Reason [1781], B310/A255)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.362
A Reaction
Yet another philosopher confusing ontology and epistemology! Every day we go beyond our experiences by inference (smoke means fire). Metaphysics is the inference of the nature of things in themselves, from within our prison of appearances.
Related Idea
Idea 21453 Leibnizian monads qualify as Kantian noumena [Gardner]