A substance that was persistently present in space yet without filling it (like that intermedi ate thing between matter and thinking beings, which some would in troduce), or a special fundamental power of our mind to intuit the future (not merely, say, to deduce it), or, finally, a faculty of our mind to stand in a community of thoughts with other men (no matter how distant they may be) these are concepts the possibility which is en tirely groundless, because it cannot be grounded in experience and its known laws, and without this it is an arbitrary combination of thoughts that, although it contains no contradiction, still can make no claim to objective reality, thus to the possibility of the sort of object that one would here think.