This intelligible ground does not touch the empirical questions at all, but may have to do merely with thinking in the pure understanding; and, although the effects of this thinking and acting of the pure understanding are encountered among appearances, these must nonetheless be able to be explained perfectly from their causes in appearance, in accord with natural laws, by following its merely empirical character as the supreme ground of explanation; and the intelligible character, which is the transcendental cause of the former, is passed over as entirely unknown, except insofar as it is indicated through the empirical character as only its sensible sign.