Should human law suppress all vices?

It seems that human law should suppress (cohibere) all vices:

Objection 1:  In Etymologia Isidore says, “Laws have been made in order that boldness might be held in check by fear of them.”  But boldness would not be adequately held in check if not every evil were prohibited by the law.  Therefore, human law should suppress every evil.

Objection 2:  The lawmaker’s intention is to make the citizens virtuous.  But no one can be virtuous unless he is held back from all vices.  Therefore, human law should suppress all vices.

Objection 3:  As was explained above (q. 95, a. 2), human law stems from the natural law.  But all vices are opposed to the law of nature.  Therefore, human law should suppress all vices.

But contrary to this:  De Libero Arbitrio 1 says, “It seems to me that the law written for ruling the people rightly permits those things and that God’s providence punishes them.”  But God’s providence does not punish anything except vices.  Therefore, human law rightly permits certain vices by not suppressing them.

I respond:  As has already been explained (q. 90, a. 1-2), law is posited as a certain rule or measure of human acts.  Now as Metaphysics 10 says, a measure must homogenous with what it measures, since diverse things are measured by diverse measures.  Hence, it must also be the case that laws are imposed on men according to their condition.  For as Isidore says, “The law must be possible both according to nature and also according to the customs of the country.”
Now the power or ability to act proceeds from an interior habit or disposition, and it is not the case that the same thing is possible for both someone who is virtuous and someone who lacks the habit of the virtue, just as it is not the case that the same thing is possible for both a boy and a grown man.  It is for this reason that the law made for children is not the same as the law made for adults; for many things are permitted to children which are punished by law or even vilified in adults.  Similarly, many things are permitted to men who are not perfected in virtue which would not tolerable in virtuous men.
Now human law is made for the multitude of men, and the greater part of this multitude consists of men who are not perfected in virtue.  And so not all the vices from which virtuous men abstain are prohibited by human law.  Instead, the only vices prohibited are the more serious ones, which it is possible for the greater part of the multitude to abstain from—especially those vices which are harmful to others and without the prohibition of which human society could not be conserved.  For instance, homicide and theft and other vices of this sort are prohibited by human law.

Reply to objection 1:  ‘Boldness’ here has to do, it seems, with attacks against others.  Hence, it mainly oncerns those sins by which injury is inflicted on one’s neighbors.  As has been explained, these are the sins prohibited by human law.

Reply to objection 2:  Human law has the intention of leading men to virtue—but leading them gradually and not all at once.  And so it does not immediately impose upon the multitude of imperfect men what is already characteristic of virtuous, viz., that they abstain from every evil.  Otherwise, those who are imperfect, unable to bear precepts of the sort in question, would erupt into worse evils—this according to Proverbs 30:33 (“He who violently blows his nose brings forth blood”) and Matthew 9:17 (“If new wine” (read:  the precepts of the perfect life) “is put into old wineskins” (read:  into imperfect men), “then the wineskins burst and the wine runs out” (read: the precepts are despised and out of contempt the men erupt into worse evils).)

Reply to objection 3:  The natural law exists in us as a certain participation in the eternal law, but human law falls short of the eternal law.  For in De Libero Arbitrio 1 Augustine says, “This law which is imposed to rule the civil communities allows and leaves unpunished many things that will be punished by God’s providence.  Nor is it the case that because this law does not do all things, it should be blamed for the things it does do.”  Hence, human law likewise cannot prohibit everything that the law of nature prohibits.