The cause is this: Although both are appear ances, the appearance before outer sense has something standing and abiding in it, which supplies a substratum grounding the transitory de terminations, and thus also a synthetic concept, namely that of space and of an appearance in it; whereas time, which is the only form of our inner intuition, has in it nothing abiding, and hence gives cognition only of a change of determinations, but not of the determinable object.