Objection 3: Further, by voluntary contrition those sins are blotted out which we committed voluntarily. But ignorance takes away voluntariness, as the Philosopher declares (Ethic. iii, 1). Therefore contrition need not cover things which have occurred through ignorance.
Objection 4: Further, we need not be contrite for a sin which is not removed by contrition. Now some sins are not removed by contrition, e.g. venial sins, that remain after the grace of contrition. Therefore there is no need to have contrition for all one's past sins.
On the contrary, Penance is a remedy for all actual sins. But penance cannot regard some sins, without contrition regarding them also, for it is the first part of Penance. Therefore contrition should be for all one's past sins.
Further, no sin is forgiven a man unless he be justified. But justification requires contrition, as stated above (Q[1], A[1]; FS, Q[113]). Therefore it is necessary to have contrition for all one's sins.
I answer that, Every actual sin is caused by our will not yielding to God's law, either by transgressing it, or by omitting it, or by acting beside it: and since a hard thing is one that is disposed not to give way easily, hence it is that a certain hardness of the will is to be found in every actual sin. Wherefore, if a sin is to be remedied, it needs to be taken away by contrition which crushes it.
Reply to Objection 1: As clearly shown above (A[2], ad 1), contrition is opposed to sin, in so far as it proceeds from the choice of the will that had failed to obey the command of God's law, and not as regards the material part of sin: and it is on this that the choice of the will falls. Now the will's choice falls not only on the acts of the other powers, which the will uses for its own end, but also on the will's own proper act: for the will wills to will something. Accordingly the will's choice falls on that pain or sadness which is to be found in the sin of envy and the like, whether such pain be in the senses or in the will itself. Consequently the sorrow of contrition is opposed to those sins.
Reply to Objection 2: One may forget a thing in two ways, either so that it escapes the memory altogether, and then one cannot search for it; or so that it escapes from the memory in part, and in part remains, as when I remember having heard something in general, but know not what it was in particular, and then I search my memory in order to discover it. Accordingly a sin also may be forgotten in two ways, either so as to remain in a general, but not in a particular remembrance, and then a man is bound to bethink himself in order to discover the sin, because he is bound to have contrition for each individual mortal sin. And if he is unable to discover it, after applying himself with due care, it is enough that he be contrite for it, according as it stands in his knowledge, and indeed he should grieve not only for the sin, but also for having forgotten it, because this is owing to his neglect. If, however, the sin has escaped from his memory altogether, then he is excused from his duty through being unable to fulfill it, and it is enough that he be contrite in general for everything wherein he has offended God. But when this inability is removed, as when the sin is recalled to his memory, then he is bound to have contrition for that sin in particular, even as a poor man, who cannot pay a debt, is excused, and yet is bound to, as soon as he can.
Reply to Objection 3: If ignorance were to remove altogether the will to do evil, it will excuse, and there would be no sin: and sometimes it does not remove the will altogether, and then it does not altogether excuse, but only to a certain extent: wherefore a man is bound to be contrite for a sin committed through ignorance.
Reply to Objection 4: A venial sin can remain after contrition for a mortal sin, but not after contrition for the venial sin: wherefore contrition should also cover venial sins even as penance does, as stated above (Sent. iv, D, 16, Q[2], A[2], qu. 2; XP, Q[87], A[1]).
Whether a man is bound to have contrition for his future sins?
Objection 1: It would seem that a man is bound to have contrition for his future sins also. For contrition is an act of the free-will: and the free-will extends to the future rather than to the past, since choice, which is an act of the free-will, is about future contingents, as stated in Ethic. iii. Therefore contrition is about future sins rather than about past sins.
Objection 2: Further, sin is aggravated by the result that ensues from it: wherefore Jerome says [*St. Basil asserts this implicitly in De Vera Virgin.] that the punishment of Arius is not yet ended, for it is yet possible for some to be ruined through his heresy, by reason of whose ruin his punishment would be increased: and the same applies to a man who is judged guilty of murder, if he has committed a murderous assault, even before his victim dies. Now the sinner ought to be contrite during that intervening time. Therefore the degree of his contrition ought to be proportionate not only to his past act, but also to its eventual result: and consequently contrition regards the future.
On the contrary, Contrition is a part of penance. But penance always regards the past: and therefore contrition does also, and consequently is not for a future sin.
I answer that, In every series of things moving and moved ordained to one another, we find that the inferior mover has its proper movement, and besides this, it follows, in some respect, the movement of the superior mover: this is seen in the movement of the planets, which, in addition to their proper movements, follow the movement of the first heaven. Now, in all the moral virtues, the first mover is prudence, which is called the charioteer of the virtues. Consequently each moral virtue, in addition to its proper movement, has something of the movement of prudence: and therefore, since penance is a moral virtue, as it is a part of justice, in addition to its own act, it acquires the movement of prudence. Now its proper movement is towards its proper object, which is a sin committed. Wherefore its proper and principal act, viz. contrition, essentially regards past sins alone; but, inasmuch as it acquires something of the act of prudence, it regards future sins indirectly, although it is not essentially moved towards those future sins. For this reason, he that is contrite, is sorry for his past sins, and is cautious of future sins. Yet we do not speak of contrition for future sins, but of caution, which is a part of prudence conjoined to penance.
Reply to Objection 1: The free-will is said to regard future contingents, in so far as it is concerned with acts, but not with the object of acts: because, of his own free-will, a man can think about past and necessary things, and yet the very act of thinking, in so far as it is subject to the free-will, is a future contingent. Hence the act the contrition also is a future contingent, in so far as it is subject to the free-will; and yet its object can be something past.
Reply to Objection 2: The consequent result which aggravates a sin was already present in the act as in its cause; wherefore when the sin was committed, its degree of gravity was already complete, and no further guilt accrued to it when the result took place. Nevertheless some accidental punishment accrues to it, in the respect of which the damned will have the more motives of regret for the more evils that have resulted from their sins. It is in this sense that Jerome [*Basil] speaks. Hence there is not need for contrition to be for other than past sins.
Whether a man ought to have contrition for another's sin?
Objection 1: It would seem that a man ought to have contrition for another's sin. For one should not ask forgiveness for a sin unless one is contrite for it. Now forgiveness is asked for another's sin in Ps. 18:13 : "From those of others spare thy servant." Therefore a man ought to be contrite for another's sins.
Objection 2: Further, man is bound, ought of charity, to love his neighbor as himself. Now, through love of himself, he both grieves for his ills, and desires good things. Therefore, since we are bound to desire the goods of grace for our neighbor, as for ourselves, it seems that we ought to grieve for his sins, even as for our own. But contrition is nothing else than sorrow for sins. Therefore man should be contrite for the sins of others.
On the contrary, Contrition is an act of the virtue of penance. But no one repents save for what he has done himself. Therefore no one is contrite for others' sins.
I answer that, The same thing is crushed [conteritur] which hitherto was hard and whole. Hence contrition for sin must needs be in the same subject in which the hardness of sin was hitherto: so that there is no contrition for the sins of others.
Reply to Objection 1: The prophet prays to be spared from the sins of others, in so far as, through fellowship with sinners, a man contracts a stain by consenting to their sins: thus it is written ( Ps. 17:27 ): "With the perverse thou wilt be perverted."
Reply to Objection 2: We ought to grieve for the sins of others, but not to have contrition for them, because not all sorrow for past sins is contrition, as is evident for what has been said already.
Whether it is necessary to have contrition for each mortal sin?
Objection 1: It would seem that it is not necessary to have contrition for each mortal sin. For the movement of contrition in justification is instantaneous: whereas a man cannot think of every mortal sin in an instant. Therefore it is not necessary to have contrition for each mortal sin.