The Enchiridion 105
105 Man Was So Created as to Be Able to Choose Either Good or Evil: in the Future Life, the Choice of Evil Will Be Impossible PL 40, 281
Now it was expedient that man should be at first so created, as to have it in his power both to will what was right and to will what was wrong; not without reward if he willed the former, and not without punishment if he willed the latter. But in the future life it shall not be in his power to will evil; and yet this will constitute no restriction on the freedom of his will. On the contrary, his will shall be much freer when it shall be wholly impossible for him to be the slave of sin. We should never think of blaming the will, or saying that it was no will, or that it was not to be called free, when we so desire happiness, that not only do we shrink from misery, but find it utterly impossible to do otherwise. As, then, the soul even now finds it impossible to desire unhappiness, so in future it shall be wholly impossible for it to desire sin. But God’s arrangement was not to be broken, according to which He willed to show how good is a rational being who is able even to refrain from sin, and yet how much better is one who cannot sin at all; just as that was an inferior sort of immortality, and yet it was immortality, when it was possible for man to avoid death, although there is reserved for the future a more perfect immortality, when it shall be impossible for man to die.
Voluntas hominis ad bonum et malum aliter libera in primo statu, aliter in ultimo. Sic enim oportebat prius hominem fieri, ut et bene velle posset, et male; nec gratis, si bene; nec impune, si male: postea vero sic erit, ut male velle non possit; nec ideo libero carebit arbitrio. Multo quippe liberius erit arbitrium, quod omnino non poterit servire peccato. Neque enim culpanda est voluntas, aut voluntas non est, aut libera dicenda non est, qua beati esse sic volumus, ut esse miseri non solum nolimus, sed nequaquam prorsus velle possimus. Sicut ergo anima nostra etiam nunc nolle infelicitatem, ita nolle iniquitatem semper habitura est. Sed ordo praetermittendus non fuit, in quo Deus voluit ostendere quam bonum sit animal rationale quod etiam non peccare possit, quamvis sit melius quod peccare non possit: sicut minor fuit immortalitas, sed tamen fuit, in qua posset etiam non mori, quamvis major futura sit in qua non possit mori.