a. Opinion of Others and its Refutation

52. About the fourth [n.43] it is said [Gratian, Decretum, p.2 cause 33 q.3, d.3 chs.39-49; Lombard, Sent. IV d.15 chs.1-3; Richard of Middleton, Sent. IV d.15 princ.1 q.5] that although exterior satisfaction for one sin could be separated from satisfaction for another, as when someone prays then does not give alms, yet exterior satisfaction cannot be so done for one sin that he remain in some other sin. And the proof is that he would please God as to one sin and still be God’s enemy. And, to this extent, the satisfactions must be conjoined at any rate in the will, at least in habit though not in effect or as actually in the will.

53. But this opinion seems too hard against sinners, and an to be occasion for greater obstinacy. For if someone who is truly repentant today, and who is humbly taking on the satisfaction (let it be a fast of three days), falls back tomorrow into mortal sin and, not being penitent about that sin, fasts on the third day because it was imposed on him -if you say that the fast on the third day is not an exterior satisfaction, there is much occasion for inducing the one who has lapsed not to fast on the third day, and so occasion for new mortal sin, because in his transgressing this penitence received from the priest there seems to be mortal sin, since there is transgression of a precept of the Church and of the vicar of God in this act.

54. Herefrom can the following argument be formed: if after a lapse, and before complete penitence, someone not carry out the original satisfaction imposed on him, he sins mortally with a new sin; therefore if he do carry it out he does well, because he does an act of obedience; but he only does an act of obedience insofar as it is imposed on him as part of his satisfaction.