It would be out of place here to adduce more examples:  a detailed treatment of the virtues and commandments will make things clearer.  For the moment it is necessary and sufficient to know that a commandment may prescribe many virtues, a virtue may impose many obligations, and there is a specifically different sin for each obligation violated.

But we can go much farther than this in wrongdoing, and must count one sin every time the act is committed.

“Yes, but how are we to know when there is one act or more than one act!  An act may be of long or short duration.  How many sins do I commit if the act lasts, say, two hours?  And how can I tell where one act ends and the other begins?”

In an action which endures an hour or two hours, there may be one and there may be a dozen acts.  When the matter a sinner is working on is a certain, specified evil, the extent to which he prevaricates numerically depends upon the action of the will.  A fellow who enters upon the task of slaying his neighbor can kill but once in fact; but he can commit the sin of murder in his soul once or a dozen times.  It depends on the will.  Sin is a deliberate transgression, that is, first of all an act of the will.  If he resolves once to kill and never retracts till the deed of blood is done, he sins but once.  If he disavows his resolution and afterwards resolves anew, he repeats the sin of murder in his soul as often as he goes through this process of will action.  This sincere retraction of a deed is called moral interruption and it has the mysterious power of multiplying sins.

Not every interruption is a moral one.  To put the matter aside for a certain while in the hope of a better opportunity, for the procuring of necessary facilities or for any other reason, with the unshaken purpose of pursuing the course entered upon, is to suspend action; but this action is wholly exterior, and does not affect the will.  The act of the will perseveres, never loses its force, so there is no moral, but only a physical, interruption.  There is no renewal of consent for it has never been withdrawn.  The one moral act goes on, and but one sin is committed.

Thus, of two wretches on the same errand of crime, one may sin but once, while the other is guilty of the same sin a number of times.  But the several sins last no longer than the one.  Which is the more guilty?  That is a question for God to decide; He does the judging, we do the counting.

This possible multiplication of sin where a single act is apparent emphasizes the fact that evil and good proceed from the will.  It is by the will primarily and essentially that we serve or offend God, and, absolutely speaking, no exterior deed is necessary for the accomplishment of this end.

The exterior deed of sin always supposes a natural preparation of sin—­ thought, desires, resolution,—­which precede or accompany the deed, and without which there would be no sin.  It is sinful only inasmuch as it is related to the will, and is the fruit thereof.  The interior act constitutes the sin in its being; the exterior act constitutes it in its completeness.