In current theology the possibility of conclusive arguments for the existence of God is largely rejected by reference to Hume or Kant. Purportedly post-metaphysical surrogates are put in place of a metaphysically founded theology, where either the existence of God may be believed in only as a rational possibility, or else a radical constructivism about the existence of God is fallen into. Nevertheless, in the following, a conclusive metaphysical argument for the existence of God in the tradition of scholastic metaphysics (...) is formulated. It is shown that theological talk of creatio ex nihilo is only the other side of this metaphysical argument: Whoever accepts creatio ex nihilo cannot consistently deny the soundness of the argument. (shrink)