Is it because what is generated does not yet exist, and because movement could not exist in non-being?
Even if matter is no more than a weak, confused image, it is not non-being.
It cannot be an appearance behind which there is no reality, for non-being cannot appear.
The expression not mortal does not indicate that a non-being is cogitated in the object; it does not concern the content at all.
The principle "ex nihilo nihil" forbids us to assume that motion can arise out of immobility, being out of non-being.
Moreover, suppose that the question to be asked is this: "Is being or non-being the real nature of the thing?"
But still, how can one say that the intelligible being is constituted by a non-being?
If matter be none of the beings which are therein, and if these really are beings, matter must be non-being.
Natura is the name for the universal, the totality of all things, containing in itself being and non-being.
Science, or real knowledge, belongs to Being, and ignorance to non-Being.