Distinction I

GRATIAN. The human race is governed by two things, namely, natural law and customs. The law of nature is that which is contained in the Law and the Gospel, by which each person is commanded to do to another what he wishes to be done to himself, and is forbidden to inflict upon another what he would not wish to be done to himself. Hence Christ in the Gospel: “All things whatsoever you wish men to do to you, do you also the same to them. For this is the Law and the Prophets.” Hence Isidore says in Book V of the Etymologies [c. 2]:

All laws are either divine or human. Divine laws stand by nature, human laws by customs, and therefore these differ, since different laws please different nations. §1. Fas is divine law; ius is human law. To pass through another’s field is permitted by divine law, but is not permitted by human law.

GRATIAN. From the words of this authority it is plainly given to be understood in what divine and human law differ from one another, since everything that is permitted by divine law is understood under the name of divine or natural law, while under the name of human law are understood customs committed and handed down in juridical writing. §1. Ius, moreover, is a general term containing many species under itself. Hence Isidore says in the same book [Etymologies, c. 3]:

Ius is a general term; lex, however, is a species of ius. Ius is so called because it is just. All ius, moreover, consists of laws and customs.

[Isidore, same chapter 3.] A law is a written enactment.

[Isidore, same chapter 3 and Book II, c. 10.] Custom is a longstanding usage, drawn solely from customary practices.

[Isidore, same chapter 3 and Book II, c. 10.] Customary usage is a certain law instituted by customs, which is received in place of law when law is lacking. §1. Nor does it matter whether it rests upon writing or upon reason, since reason also commends law. §2. Moreover, if law consists in reason, everything that rests upon reason will already be law, provided that it accords with religion, agrees with discipline, and conduces to salvation. §3. It is called customary usage because it is in common use.

GRATIAN. Therefore, when it is said, “it does not matter whether customary usage rests upon writing or upon reason,” it appears that customary usage has in part been reduced to writing, and in part has been preserved only in the customs of those who use it. That which has been reduced to writing is called an enactment or law; that which has not been reduced to writing is called by the general name, namely, customary usage. §1. There is also another division of law, as Isidore attests in the same book [V, c. 4], saying thus:

[Isidore, same chapter 4.] Law is either natural, civil, or of nations.

[Isidore, same chapter 4.] Natural law is common to all nations, because it is held everywhere by the instinct of nature, not by any enactment, such as the union of man and woman, the succession and upbringing of children, the common possession of all things and the one liberty of all, the acquisition of those things that are taken from the sky, the earth, and the sea; likewise the restoration of a thing deposited or of money entrusted, and the repelling of violence by force. §1. For this, or anything similar to it, is never held to be unjust, but natural and equitable.

[Isidore, same chapter 5.] Civil law is that which each people or city establishes as its own for a divine or human reason.

[Isidore, same chapter 6.] The law of nations concerns the occupation of sites, building, fortification, wars, captivities, servitudes, rights of return, treaties of peace, truces, the religious obligation not to violate envoys, and marriages prohibited between foreigners. §1. This is accordingly called the law of nations, because almost all nations use this law.

[Isidore, same chapter 7.] Military law concerns the formalities of making war, the obligation of making a treaty, the advance against the enemy or the engagement when the signal has been given; likewise the retreat when the signal has been given; likewise the punishment of a military offense if a position is deserted; likewise the measure of stipends, the grades of dignities, and the honor of rewards, as when a crown or torque is bestowed; likewise the adjudication of booty, its just division according to the qualities and labors of persons, and the prince’s share.

[Isidore, same chapter 8.] Public law concerns sacred things, priests, and magistrates.

[Isidore, same chapter 9.] The law of the Quirites belongs properly to the Romans, and none possess it except the Quirites, that is, the Romans. §1. It treats of lawful inheritances, curatorships, guardianships, and acquisitions by prescription, which laws are found among no other people but are proper to the Romans and established for them alone.