Ryall offers a transcendental proof of the existence of an external world in support of his claim that "our cognition conforms to objects". If space and time are "immanent" in nature then nothing would prevent our experiencing ourselves in an objective sense since this presumed capacity we have to render the world ought to provide as clear a perspective on one's physical self as on any other object; but this is not the case in respect of observer motion. Thus Kant's idealism deduces its own absurdity in first denying that we apprehend things in a "transcendent" sense and then suggesting that space and time are internally derived, in which case there ought to be no barrier at all to our perceiving ourselves as we revolve through space.