(CG 4/92). That the Souls of the Saints after Death have their Will immuta... (Book 4. God, in His Revelation) (Summa Contra Gentiles) (Aquinas, Thomas, St.)

THE very disorder of the will is a punishment and a very great affliction, because insomuch as a person has a disordered will, everything that is done rightly displeases him: thus it will displease the damned to see the will of God fulfilled in all things, that will which they have sinfully resisted.

3. The will is changed from sin to goodness only by the grace of God (B. III, Chapp. CLVII, CLVIII). But as the souls of the good are admitted to a perfect participation in the divine goodness, so the souls of the damned are totally excluded from grace.

4. As the good, living in the flesh, make God the ultimate end of all their doings and desires, so the wicked set up their rest in some undue end which turns them away from God. But the disembodied spirits of the good will immovably cling to the end which they have set before themselves in this life, namely, God. Therefore the souls of the wicked will immovably cling to the end which they too have chosen for themselves. As then the will of the good cannot become evil, so the will of the evil cannot become good.