Kant maintains that space is "empirically real," but is nevertheless "transcendentally ideal." He explains this saying that space "is nothing, as soon as we lay aside the condition of the possibility of all experience, and look upon it as something that underlies things in themselves' (KrV, A 28 = B 44). "It is therefore solely from the standpoint of man that we can speak of space, of extended things, etc. If we depart from the subjective condition under which alone we can have outer intuition…the representation of space means nothing at all" (KrV A26=B42). This doctrine of the transcendental ideality of space (and of time) is, he writes, one of the two hinges upon which the whole of metaphysics turns (the other is the reality of freedom — Ak., XX, 311; XVIII, 669). The importance of this doctrine in the architecture of Kant's philosophy should therefore not be underrated. There seems to be, however, some difficulty in understanding what it means. This difficulty continues to generate misunderstandings in spite of the many scholarly accounts of this matter. I feel therefore that a concise review of this question, bringing together within a short compass a few points essential to clarify it, will not be altogether useless.