Part I. On the Notion of the Act of Doing Penance

The act of doing penance consists essentially in detestation and sorrow concerning a committed sin, insofar as it is an offense against God, with the purpose of no longer sinning, or, in other words, in contrition.¹ Therefore the act of doing penance requires:

I. Detestation and sorrow. This is laid down against Luther, who taught that penance consists in recognition of one's former error and a change of purpose, with detestation and sorrow excluded. But the doctrine stated is clear:

1. From Sacred Scripture, which, besides amendment of life, requires detestation and sorrow concerning sin: "Be converted to me with all your heart, in fasting and in weeping and in mourning, and rend your hearts."² Again: "Now I rejoice, not because you were made sorrowful, but because you were made sorrowful unto penance."³

2. From the testimonies of the Fathers. Thus Tertullian,⁴ St. Cyprian,⁵ St. Augustine,⁶ St. Ambrose.⁷

3. From reason. By sinning, a man has inflicted injury upon God. But one who has inflicted injury upon God cannot expect pardon unless he repairs the injury, at least by detesting it and sorrowing over it.

II. Concerning the sin committed, insofar as it is an offense against God, or, in other words, concerning sin taken formally, so that the offense against God is the object which the sinner detests. And indeed, in order that penance be salutary, that is, that it help to reconcile man with God, the sinner must detest his very aversion from God, or sin taken formally.

III. The purpose of no longer sinning. That this is required is clear both from Sacred Scripture,⁸ and from the fact that no one can be reconciled with God unless the will is simply opposed to offense against God. But such a will involves the purpose, at least implicit, of no longer sinning.

Corollary I. The act of doing penance can proceed from the motive both of the virtue of penance and of another virtue to which sin is opposed. Moreover, to some virtues, for example charity, religion, gratitude toward God - which are called universal - all sins are opposed; hence from the motive of these virtues we can repent of all sins. But to others, which are called particular, only particular sins are opposed, for example lust to chastity; hence from the motive of those virtues an act of doing penance cannot be elicited except concerning a particular sin.

Corollary II. The act of doing penance concerning sin considered under the aspect of an offense against God is simply an act of the virtue of penance. But if the said act is elicited under the influence of the motive of another virtue, there is an act elicited by the virtue of penance, but commanded by that virtue whose motive is specifically proper. The reason for the former is that an act is specified from the formal object which; but in this case sin is considered under the aspect of offense against God, which is the formal object which of the virtue of penance. The latter is set forth by St. Thomas in these words: "This is the difference between eliciting an act and commanding: that a habit or power elicits that act which it produces with no intermediary; but it commands an act which is produced by means of an inferior power or habit concerning the object of that power" (3, distinction 27, question 2, article 4, solution 3).

¹ Cf. Council of Trent, session 14, chapter 4.

² Joel 2:12.

³ 2 Corinthians 7:9.

⁴ De Poenitentia, chapter 9.

⁵ De lapsis, n. 35 (Migne, Patrologia Latina, vol. 4, col. 492).

⁶ Sermon 351, chapter 5, n. 12 (ed. Gaume, vol. 5, col. 2019).

⁷ De Poenitentia, book II, chapter 10.

⁸ Cf. Ezekiel 18:31 sq.