Whose reason is it that makes law?

It seems that everyone’s reason makes law:

Objection 1:  In Romans 2:14 the Apostle says, “For when the Gentiles, who do not have the Law, do by nature those things that are of the Law, they, not having the Law, are a law unto themselves.”  But he says this in general about everyone.  Therefore, everyone is able to make law for himself.

Objection 2:  As the Philosopher says in Ethics 2, the lawmaker’s intent is to lead men to virtue.  But every man is capable of leading another to virtue.  Therefore, every man’s reason can make law.

Objection 3:  Just as the ruler (princeps) of a city is the one who governs (gubernator) the city, so too every father of a family (paterfamilias) is the one who governs the household.  But the ruler of a city is able to make law in the city.  Therefore, every father of family is able to make law in his own household.

But contrary to this:  In the Etymologia Isidore says (and Decretals, dist. 2 repeats this), “A law is an ordinance (constitutio) of the people, by which the elders (maiores), along with the common people (plebes), have sanctioned something.”  Therefore, it is not just anyone’s function to make law.

I respond:  Law has to do properly, primarily, and principally with an ordering toward the common good.  Now to order something toward the common good is the role either of the whole multitude or of someone who is acting in the place of the whole multitude.  Therefore, establishing a law is something that belongs either to the whole multitude or to a public personage who is in charge of (habet curam) the whole multitude.  For in all other cases as well, ordering something to an end is the role of one for whom that end is his own.

Reply to objection 1:  As was explained above (a. 1), when law exists something, it exists not only in that which regulates, but also, by participation, in that which is regulated.  And everyone is a law unto himself in the sense that he participates in the order of that which is doing the regulating.  This is why the Apostle adds immediately in the same place, “... who show the work of the law that is written in their hearts.”

Reply to objection 2:  A private person cannot efficaciously lead anyone to virtue.  For he can only issue a warning, and if his warning is not heeded, he does not have the sort of coercive power (vim coactivam) which, according to the Philosopher in Ethics 9, law must have in order to lead someone efficaciously to virtue.  Now, as will be explained below (q. 92, a. 2), this coercive power is had by the multitude or public personage whose role it is to inflict punishments.  Only someone like this is in a position to make laws.

Reply to objection 3:  Just as a man is part of a household, so a household is part of a city and, as Politics 1 puts it, a city is a complete community (communitas perfecta).  And so just as the good of a single man is not the ultimate end, but is instead ordered toward the ultimate end, so too the good of a single household is ordered toward the good of the a single city, which is a complete community. Hence, one who governs a family can, to be sure, make certain precepts and statutes, but these do not properly speaking have the character of law.