Roman Catechism 19.69

Chapter 19 — Part II: The Sacraments — Penance

Section 69. Conditions Required for Contrition — From what has been said we may gather the chief requisites of true contrition. In these the faithful are to be accurately instructed, that each may know the means of attaining, and may have a fixed standard by which to determine, how far he may be removed from the perfection of this virtue.