Chapter 19 — Part II: The Sacraments — Penance
Section 144. Necessity Of Satisfaction — Such being the nature of satisfaction, it will not be difficult to convince the faithful of the necessity imposed on the penitent of performing works of satisfaction. They are to be taught that sin carries in its train two evils, the stain and the punishment. Whenever the stain is effaced, the punishment of eternal death is forgiven with the guilt to which it was due; yet, as the Council of Trent declares, the remains of sin and the temporal punishment are not always remitted.