SECOND ARTICLE [I-II, Q. 97, Art. 2]

Whether Human Law Should Always Be Changed, Whenever Something Better

Occurs?

Objection 1: It would seem that human law should be changed, whenever

something better occurs. Because human laws are devised by human

reason, like other arts. But in the other arts, the tenets of former

times give place to others, if something better occurs. Therefore the

same should apply to human laws.

Obj. 2: Further, by taking note of the past we can provide for the

future. Now unless human laws had been changed when it was found

possible to improve them, considerable inconvenience would have

ensued; because the laws of old were crude in many points. Therefore

it seems that laws should be changed, whenever anything better occurs

to be enacted.

Obj. 3: Further, human laws are enacted about single acts of man. But

we cannot acquire perfect knowledge in singular matters, except by

experience, which "requires time," as stated in _Ethic._ ii.

Therefore it seems that as time goes on it is possible for something

better to occur for legislation.

_On the contrary,_ It is stated in the Decretals (Dist. xii, 5): "It

is absurd, and a detestable shame, that we should suffer those

traditions to be changed which we have received from the fathers of

old."

_I answer that,_ As stated above (A. 1), human law is rightly

changed, in so far as such change is conducive to the common weal.

But, to a certain extent, the mere change of law is of itself

prejudicial to the common good: because custom avails much for the

observance of laws, seeing that what is done contrary to general

custom, even in slight matters, is looked upon as grave.

Consequently, when a law is changed, the binding power of the law is

diminished, in so far as custom is abolished. Wherefore human law

should never be changed, unless, in some way or other, the common

weal be compensated according to the extent of the harm done in this

respect. Such compensation may arise either from some very great and

every evident benefit conferred by the new enactment; or from the

extreme urgency of the case, due to the fact that either the existing

law is clearly unjust, or its observance extremely harmful. Wherefore

the Jurist says [*Pandect. Justin. lib. i, ff., tit. 4, De Constit.

Princip.] that "in establishing new laws, there should be evidence of

the benefit to be derived, before departing from a law which has long

been considered just."

Reply Obj. 1: Rules of art derive their force from reason alone: and

therefore whenever something better occurs, the rule followed

hitherto should be changed. But "laws derive very great force from

custom," as the Philosopher states (Polit. ii, 5): consequently they

should not be quickly changed.

Reply Obj. 2: This argument proves that laws ought to be changed: not

in view of any improvement, but for the sake of a great benefit or in

a case of great urgency, as stated above. This answer applies also to

the Third Objection.

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Summa Theologica, Part I-II (Pars Prima Secundae) From the Complete American Edition · 第 625 / 746 题