Should human law always be changed
when something better comes along?
It seems that human law should always
be changed when something better comes along:
Objection 1: Human laws, like
other matters of art, have been arrived at by human
reason. But in other matters of art, what was previously
embraced is changed if something better comes along.
Therefore, the same thing should be done in the case of
We can provide for the future by drawing on the past. But
if human laws had not been changed to better discoveries
that superceded them, then many anomalies would have
followed, because old codes of law contain many elements
of ignorance. Therefore, it seems that the laws should be
changed as often as something better to institute comes
Human laws are established with respect to particular
human acts. But the only way we come to complete
cognition of particulars is through experience, which
takes time, as Ethics 2 points out. Therefore, it
seems that through the course of time something better to
institute can come along.
But contrary to this:
Decretals, dist. 12, says, “It is a ridiculous and
wholly abominable disgrace for us to break off the
traditions that we have received from our fathers.”
As has been explained (a. 1), human law is justifiably
changed to the extent that such a change in the law
is a means of providing for the common welfare.
However, the very changing of the law, taken just by
itself, does a certain sort of damage to the common
welfare. For custom (consuetudo) contributes
to the observance of a great many laws, to the extent
that whatever violates common custom—even if it is less
important in itself—is seen as rather serious.
Hence, when a law is changed, the constraining force
of the law is diminished to the extent that a given
custom is nullified.
human law should never be changed unless the damage
done to the common welfare by the change is wholly compensated
for in some other way. This happens either (a)
because some very great and obvious advantage comes
from the new statute, or (b) because there is some very
great necessity in virtue of the fact that the established
law either involves some manifest iniquity or is such
that its observance is very harmful. Hence, the
Legal Expert says, “In order to revoke a law that has
been deemed just for a long time, there must be an obvious
advantage in the new practices that are going to be
Reply to objection 1:
Matters of art have their efficacy solely from reason, and
so whenever a better reason comes along, what was
previously embraced should be changed. By contrast, as
the Philosopher points out in Politics 2, laws
acquire an especially great force from custom. And so
they are not to be changed so easily.
Reply to objection 2:
This argument shows that laws should be changed, but not
for the sake of just any sort of improvement. Instead, as
has been explained, they should be changed for the sake of
some great advantage or because of some great necessity.
Reply to objection 3:
The same reply holds for the third objection.