Space (n.) is no discursive, general conception of the relations of things, but a pure intuition. Space is essentially one, we can only represent to ourselves one space, -the notion of this or that space, depends solely upon limitations.
Space (n.) is not an object that exist apart from our experience. It is the shape of our outer experience. It is empirically real but in a transcendental way. That is to say, while it is easy to imagine space as empty, we cannot imagine our outer sense as being absent of space. As such, space is both something and nothing at all.
Space (n.) is the formal condition whereby we represent to ourselves objects as being without us. It is not external representations, but representations insofar as they are of an external sort. Time is all that relates to internal determinations. As such, we cannot have an external intuition of time or an internal intuition of space.
Space (n.) is, along with time, not a thing perceived, but a mode of perception, an organ of perception, a way of putting sense into sensation.
Space (n.) is, along with time, a priori because it is inconceivable that we should ever have any future experience that will not also involve it.
Space (n.) is, along with time, a priori, because all ordered experience involves and presupposes it, and without it, sensations could never grow into perceptions.