Immanuel Kant,
Critique of Pure Reason
(1791)
“ In the transcendental aesthetic we proved that everything intuited in space and time, all objects of a possible experience, are nothing but phenomena, that is, mere representations; and that these, as presented to us—as extended bodies, or as series of changes—have no self-subsistent existence apart from human thought. This doctrine I call Transcendental Idealism.* The realist in the transcendental sense regards these modifications of our sensibility, these mere representations, as things subsisting in themselves. ”
