The Enchiridion 104
104 God, Foreknowing the Sin of the First Man, Ordered His Own Purposes Accordingly PL 40, 281
Wherefore, God would have been willing to preserve even the first man in that state of salvation in which he was created, and after he had begotten sons to remove him at a fit time, without the intervention of death, to a better place, where he should have been not only free from sin, but free even from the desire of sinning, if He had foreseen that man would have the steadfast will to persist in the state of innocence in which he was created. But as He foresaw that man would make a bad use of his free-will, that is, would sin, God arranged His own designs rather with a view to do good to man even in his sinfulness, that thus the good will of the Omnipotent might not be made void by the evil will of man, but might be fulfilled in spite of it.
Quae fuerit voluntas Dei erga Adamum, quem peccaturum praesciebat. Quapropter etiam primum hominem Deus in ea salute in qua conditus erat, custodire voluisset, eumque opportuno tempore post genitos filios sine interpositione mortis ad meliora perducere, ubi jam non solum peccatum non committere, sed nec voluntatem posset habere peccandi, si ad permanendum sine peccato, sicut factus erat, perpetuam voluntatem habiturum esse praescisset. Quia vero eum male usurum libero arbitrio, hoc est peccaturum esse praesciebat, ad hoc potius praeparavit voluntatem suam, ut bene ipse faceret etiam de male faciente, ac sic hominis voluntate mala non evacuaretur, sed nihilominus impleretur omnipotentis bona.