Introduction by Robert Pasnau

Thomas says: "It happens that something must be chosen according to one considered condition of the matter, although it should not be chosen if all the applicable conditions were considered, and so there can be error in the choices of angels, and sin."

Original Latin

Never before in English...

These selections are from Aquinas’s first major work, his commentary on Peter Lombard’s Sentences. Aquinas’s commentary has never been published in English, and if you were to write out an English translation of these selections, you might be the first person ever to do so!

How can angels sin?

Aquinas begins by asking how can there be sin in an angel. The key issue is whether the angels' sin arose out of some kind of ignorance, or out of some kind of passion, or in some other way.

Aquinas also considers the most famous alleged motivation of the fallen angels: their desire to be equal to God. Given everything that has been said so far, one might wonder whether the story about the angels' fall from grace can make any sense. After all, if the angels are so smart, how could they have wanted something that is clearly just impossible for them to have? This is the question that Aquinas asks too, but he finds a way to accept the traditional story without having to conclude that those fallen angels must just not have been very smart.

When Did Angels Fall?

Aquinas also asks another fascinating question: how long was it, after being created, before the fallen angels sinned?

Aquinas thinks there are different possible answers to this question, but the answer he regards as preferable is that the fallen angels sinned right away, the very moment they were created. It is interesting to consider this answer in light of Aquinas' insistence that the fallen angels were not bad by nature.