ST Suppl., q. 16
Of Those Who Receive the Sacrament of Penance
Supplement — compiled posthumously from Aquinas's early Sentences commentary
We must now consider the recipients of the sacrament of Penance: under which head there are three points of inquiry:
(1) Whether penance can be in the innocent?
(2) Whether it can be in the saints in glory?
(3) Whether in the good or bad angels?