Chapter I. On the Nature and Properties of Law

81. • DEFINITION. Law is an ordination of reason unto the common good, promulgated by him who has care of the community (St. Thomas, 1.2, q. 90, no. 4). Hence it differs from a precept. For law is essentially made for a community by a public person and for the common good, while a precept properly so called can also emanate from a private person, and can regard private subjects unto their private good. Such is the command of a father over a son, or of a Prince over some subject. Yet often laws also are called precepts. Thus the divine laws handed down to Moses on the mountain are called the precepts of the Decalogue.

There is a manifold distinction between law and precept, namely 1. by reason of the one commanding, because the legislator is a public person, but the one giving a precept can be a private person. 2. By reason of the subject, because law is made for a community, but a precept even for a private person. 3. By reason of the end, because the end of law is the common good, but the end of a precept is private good ¹. 4. By reason of place, because law affects the territory, but a precept affects the person, and, as they say, clings to the bones. 5. By reason of duration, because a precept ceases by the death of the one commanding, but law is not extinguished together with the legislator.

¹ Understand the direct and immediate end; for mediately and indirectly law tends to the private good of each one, but a precept tends to the common good: namely insofar as the common good of all redounds to the good of individuals, and vice versa.

DIVISION. Law is distinguished in a manifold way:

1. Divine, or human, according as it has God or man as its immediate author.

2. Natural, or positive, according as it is intimated by rational nature itself, or by a positive act of the legislator.

3. Ecclesiastical, or civil, according as it is made by ecclesiastical or civil power.

4. Moral, or penal, or mixed, according as it obliges under fault alone, or under penalty alone, or under both at once.

5. Affirmative, or negative, according as it commands the placing of an act, or prohibits it. Hence it is also called preceptive, or prohibitive.

6. Simply prohibiting, or invalidating, or permitting, according as it only renders an act illicit, or invalid, or prohibits the agent from being disturbed.

7. Favorable, or odious, according as it restricts or enlarges liberty ².

² Law per se is always considered something odious. Yet there are laws which look to enlarging favor, or rather to lessening bonds. A law of this sort is one which declares valid marriages contracted by children under paternal power without the consent of parents, or even against their will.

8. Written, or preserved by use, according as it is made by written mandate, or is introduced and preserved by custom alone.

82. • QUESTION. What are the properties or conditions of human law?

I answer. They are the following, which are included in the very definition of law, namely, it must be possible, honest, useful, just, permanent or stable, and promulgated. - Thus from the first part of the Decretum, dist. 4, can. 2.

1. Possible, that is, accommodated to the morals and circumstances of persons, etc.

2. Honest, that is, establishing nothing that is dishonorable, and repugnant to good morals or right reason or positive divine law; for law cannot bind to evil acts and those opposed to the ultimate end of man.

3. Useful for the common good, 1. because the good of the community is the essential and primary end of law; 2. because law is an act of public power, which has been instituted for the common good alone.

4. Just, that is, according to the norm of distributive justice, so that some are not burdened more than the rest, but it is imposed on subjects with equality of proportion, considering their strength and faculties: otherwise it does not oblige in conscience.

5. Permanent, or stable, that is, established without a definite time, so that once made, unless it is abrogated, or becomes harmful or useless, it lasts as long as the community on which it is imposed stands, or as long as the circumstances for which it was made persevere.

6. Promulgated, because law is a general and public rule of actions, directing and obliging the community. But a rule cannot direct and oblige the community which it rules, unless it has been applied to it through promulgation.