Daniel Guy has an argument against creation ex nihilo:
1. Whatever is created ex nihilo is completely metaphysically dependent on God.
2. Whatever is created ex nihilo is not constituted of (or from) anything further.
3. Whatever is not constituted of (or from) anything further is constitutively independent.
4. Whatever is constitutively independent is at least partially metaphysically independent, because constitutive independence is a kind of metaphysical independence.
5. Therefore, whatever is created ex nihilo is both completely metaphysically dependent (from 1) and at least partially metaphysically independent (from 2–4).
6. Nothing can be both completely metaphysically dependent and partially metaphysically independent.
7. Therefore, nothing can be created ex nihilo.
This argument is much less bad than the usual arguments I've come across. Nonetheless, it is very obvious where the problem in the argument is; constitution-of and constitution-from are entirely distinct things but the argument, through (2) and (3), attempts to elide them. This is obvious in ordinary changes; bread is constituted from flour and water and so forth, but to become bread, the ingredients have to be modified (to get bread, you have to stop having flour through a process of mixture and thermal chemistry). Thus, in colloquial English, bread is made out of flour but is not made up of flour. This distinction, however, is also relevant here, as creation ex nihilo is a doctrine specifically and explicitly about constitution-from (that's the ex), and not constitution-of. 'Creation ex nihilo' is claiming that, while the cosmos exists because of the act of creation, there are no ingredients for the cosmos prior to creation; it is not claiming that that the created cosmos doesn't have its own constitution and constituents. But (3) and (4) only have a plausible sense for constitution-of.
Bread is a consolidated non-homogeneous foam (a) made by the baker, (b) made from the prior ingredient of flour (and water, leaven if any, etc.), and (c) made up of starch granules (and some secondary compounds) in an unstable matrix. In the doctrine of creation ex nihilo, the cosmos is a heterogeneous system (a) made by God, (b) not made from any prior ingredient, and (c) made up of things engaging in and undergoing various sorts of interactions and relations natural to them. It is dependent in the sense of (a); it is only independent in the sense that it has its own make-up and not some other make-up (c), although even there we have to be understanding this as not talking about the dependence of the cosmos on its own constituents. (Any ultimate constituents, though, would be completely independent in the sense of (c).) The 'ex nihilo', concerned with (b), does not indicate any kind of independence at all; it clarifies that the dependence in (a) is complete and exhaustive, i.e., the cosmos derives from God's act of creation and ultimately nothing other than God's act of creation. Thus the contradiction doesn't occur.
