Primitive Light and Light which is visible now must be different in kind.

For these things which they say do not occur in the case of this Darkness and Light which are here. Let them either appeal to the Light and Darkness which are here, or let them admit that this is not the same Light as exists there, but another. And if it is not the same, why do they worship this Sun if it is not the same as that which is in the Domain of the Good (Being)? And if the Light and the Darkness are not the same, then this world was not mixed and brought [P. 100, l.14.] into existence from these Natures. And whence then are these Luminaries which are in our sphere?