  The predicative reading of the argument of Book V and the analogies of the central books does not limit the range of Forms and does not commit itself to the possibility of knowledge of the external world. If one treats the physical world as metaphysically defective, as victimized in any and every respect by its being and not-being, then that suffices to preclude one from knowing anything about such a world. The objects of the physical world are simply not the right sorts of things to qualify as objects of knowledge, regardless of what sorts of reasons or justifications or explanations one has at her disposal.