Chapter 19 — Part II: The Sacraments — Penance
Section 73. Reasons For These Conditions — That a sorrow for sin and a firm purpose of avoiding sin for the future are two conditions indispensable to contrition nature and reason clearly show. He who would be reconciled to a friend whom he has wronged must regret to have injured and offended him, and his future conduct must be such as to avoid offending in anything against friendship.