Aquinas on Implicit Baptism of Desire

Taylor Marshall discusses Aquinas' articulation of an implicit baptism of desire:

Last Monday I was fascinated to learn that Saint Thomas Aquinas had articulated a doctrine of implicit baptism of desire.

As stated above (1, ad 2; 68, 2) man receives the forgiveness of sins before Baptism in so far as he has Baptism of desire, explicitly or implicitly [there are the key words]; and yet when he actually receives Baptism, he receives a fuller remission, as to the remission of the entire punishment. So also before Baptism Cornelius and others like him receive grace and virtues through their faith in Christ and their desire for Baptism, implicit or explicit: but afterwards when baptized, they receive a yet greater fullness of grace and virtues. Hence in Psalm 22:2, "He hath brought me up on the water of refreshment," a gloss says: "He has brought us up by an increase of virtue and good deeds in Baptism. Yet catechumens who die without baptism can be saved but only as through fire. That is, they are absolved of eternal punishment, not temporal punishment."

STh III, q. 69, a. 4.

The perplexing thing is that Saint Thomas Aquinas believes that baptism by desire only remits eternal punishment and not the temporal punishment due to sins.

Read the whole thing (and the comments).