§ 1. Custom makes a law and abrogates a law; or, if the severity of a prince strives against it, the law produces hatred and this hatred sedition. Therefore, a prudent legislator must above all have at heart the customs of his state. Custom is that which, without a law, has become customary just as though it were lawful—namely, right instituted by usages, which is received in place of law. Thus the author To Herennius. Isidore, in Gratian, adds to the latter definition, “when the law is lacking”; this part of the definition was taken from Tertullian, On the Soldier’s Crown. It is also called usage and practice, and signifies a frequency of acts. It is understood concerning things which someone does over a long and continuous period.
Frequency of acts introduces a habit or inclination and a certain right, from which arises an obligation to act in the same manner and to abrogate other contrary laws. Custom therefore makes right and law; prescription, however, transfers ownership, gaining strength and being confirmed by the deed of a private person, whereas custom belongs to a people.
§ 2. Custom is concerned with things and persons, with human actions, and with most matters in which law exists. One is most common and is almost the law of nations; another exists in some one state; another is private, belonging either to a person or to an imperfect community which cannot make law. Yet this is accustomed to clamor against common law. Custom is also divided into ecclesiastical and civil custom.
There is also custom according to right, beyond right, and contrary to right. Every good and legitimate custom is according to natural right—that is, consonant with it—and according to positive divine right. Next, natural right and divine right cannot be abrogated by any custom.
§ 3. A custom contrary to the law of nations can have force if you consider the nature of the matter, for the contrary of what has been received by the law of nations is not evil by nature; therefore it can be introduced by custom. By nature it can be, but in fact it cannot, because of circumstances and the enactments and concord of other nations. The example is usually brought forward of persons captured in war, who become slaves by the law of nations, although this does not occur in certain regions.
But I do not think that the law of nations is removed by Christian Europeans because they do not reduce other Christians to slavery. For the law of nations is that persons captured in war should not be killed but preserved, and for that reason they were called slaves. Therefore the primary agreement by the law of nations is that the savagery of wars should not be excessive and that the sword of the victor should not rage to extermination. Gentleness is approved in the manner of servitude, and much more if they permit the captives to be redeemed and exchanged and if they are treated kindly. I judge this to be much more according to the law of nations than the most cruel slavery under which masters possessed the right of life and death, and under which persons could be sold to wretched labors in the mines, to the beasts, and to unspeakable things. For when Cicero and others determine that liberty is to be defended even by death, they spoke not hyperbolically but from the experience of affairs; for ancient slavery was in truth more grievous than death.
Therefore, I deny that any nation can introduce a custom contrary to the law of nations, because with respect to nations and this law there is equality of the human race; nor can they change that law without the consent of the whole, since the others are bound by that law.
Next, the law of nations cannot be abolished by a contrary law of one prince, because this would occur with harm to other nations. He can determine and mitigate it, as if he should command that enemies who have surrendered be preserved; for they surrendered themselves to the mercy, not the cruelty, of the victor. He cannot abolish it except against an enemy who had himself previously violated the law of nations.
A custom beyond the law of nations can be given, just as another can be given beyond divine right. Thus, by divine right, forty blows were inflicted upon the guilty person; by the custom of the Israelites one fewer was given, lest by chance they exceed the number. Whatever custom is contrary to divine right is an abuse; it introduces no right but renders persons guilty of punishment.
Custom according to a human law confirms it; custom contrary to the law abrogates it.
To customs I refer style—that is, the manner and order of acting—and rite—that is, the solemnity of acts received by usage, so that it is now not lawful to institute the right otherwise.
§ 4. It belongs to every custom that it be just, useful, and for the sake of the common good; for what makes a law void must also be understood concerning custom. Therefore, just as bad laws, so also customs are to be abolished. Hence, just as a better custom can abrogate a worse law, so a better custom can abrogate a useless or burdensome custom. A law cannot prohibit for the future a custom contrary to itself, even if it forbids that custom to be introduced; for although it was introduced contrary to law, it is nevertheless reasonable. That it has been received into usages confirms the custom, since peoples observe the usage from agreement; for agreement inheres in custom.
Hence it is clear that a custom which is in the place of law can be introduced by a state or by a part of a state which possesses the power either to carry a law or at least to receive one; nor is it necessary that the custom be observed by all, but by the greater part.
§ 5. The force of custom therefore begins from acts and from tacit agreement, whether by acts or omissions, but is perfected through the consent of the prince. This consent is either known from a law, if, seeing a just and useful custom gaining strength, he approves it by carrying a law—and thus it is law—or, observing it, he dissembles, or at least by a common law approves all honorable and useful customs.
Now common law approves reasonable and legitimate customs. Thus distinction 1, Mos: “Because usages make a law, and common right consists of laws and usages”; distinction 1, Omnes; distinction 8, Mala; distinction 12, Omnia talia; question 16.3, Dicet: “Because the custom of those with whom we associate, if it is not depraved, must be observed”; and distinction 11, Quis: “Because the customs of the Roman Church are to be observed.”
Civil law has the same in law Forma censuali, § Si vero, On Censuses. Thus also a custom whose beginning is beyond memory sustains an aqueduct from public ground, for the prince appears to have held it valid. These things must chiefly be understood of the custom which is called prescriptive; prescription occurs between persons present over a period of ten years, and between persons absent over twenty.
A judicial sentence is not required for it to be approved; nevertheless, unless it is proved thoroughly, judgment must not easily be made according to it—except when it is prescriptive, or approved by manifest consent, or, according to most Doctors, is the interpreter of some law.
§ 6. An unjust, useless, or pernicious custom must be carefully investigated. A sign of it is if it is vehemently desired by one class of human beings, for since it is useful to them, it will be useless to the rest. Generally, the exceptional advantage of a part redounds to the harm of the whole. It must be seen whether the custom arose from evil usages; for just as good laws arise from evil usages, so depraved customs also arise from them.
Hence good laws opposed to evil usages generally appear burdensome and seem to those who prefer to live by their own usages rather than by public laws to be removable through customs. For example, it is the custom of many churches that, if someone is present on one or another day of the year, he receives what they call the Body, although during the rest of the time he has not even looked upon a church. That custom arose from plurality of benefices, and this from avarice; therefore the custom is rightly suspect.
When a custom conflicts with several laws, especially ecclesiastical laws, it is suspect. Isidore, in the Synonyms, chapter 16, says that custom yields to laws, but he appears to treat of a depraved custom. For depraved usage is overcome by reason and law. And distinction 11, chapter 2: “Let usage yield to authority; let law and reason overcome depraved usage.” And canon 4: “The authority of custom and long-standing usage is not slight; nevertheless, its importance will not have such force that it overcomes either reason or law.”
But canon 5 teaches that a custom which is shown to conflict with neither sacred canons nor human laws is inviolable. This must be understood of private and non-prescriptive customs, for it is evident that sacred canons concerning indifferent matters can be changed, as in distinction 12, chapter 7: “In those matters concerning which divine Scripture has established nothing certain, the custom of the people of God and the institutions of the ancestors are to be held as law. And just as transgressors of divine laws, so contemners of ecclesiastical customs are to be restrained.”
§ 7. I judge that custom must be carefully examined, so that, if it is evil, it can be abolished before it is strengthened. For it generally has its beginnings from evil persons; for those who begin a custom which is contrary to laws undoubtedly sin by violating the law. A good custom therefore has its origin in transgression of laws and disobedience; laws, on the contrary, have their origin from deliberation, from the senate, and from the prince. Since this is so, custom is especially dangerous in ecclesiastical matters if it removes the canons from their place.
For in civil matters a law more easily begins to be unjust and accordingly is more rightly changed; nor does its change always take its beginning from evil usages, since in very many instances its matter is of such a kind that it does not pertain to morals. But canonical laws concern divine worship and morals; they have foundations and reasons from Scripture and apostolic sanctions, and also require severity and integrity of life, so that contrary customs are generally vicious. For canonical laws concern indifferent matters far less often than civil laws; therefore the examination of customs is more exact in sacred than in profane matters.
The eleventh canon is read in distinction 44: “For reverence toward God and priests, the whole holy synod ordained that—because idle tales are accustomed frequently to be interposed at tables—a reading of the divine Scriptures should be mingled in every priestly banquet. For by this both souls are built up toward the good and unnecessary tales are prohibited.” Thus the Third Council of Toledo, chapter 7. Now that most beautiful law has been abrogated by a contrary custom, while the pontiff and bishops dissemble. Nevertheless, there is no one who does not prefer so holy a law to the custom; nor is there doubt that those who first violated the law sinned.
Therefore, the beginnings of a custom which is contrary to law are generally shameful, introduced by the worse part of the city, especially in ecclesiastical matters, which were established excellently from the beginning.
For the account of the earthly city is altogether different from that of the ecclesiastical city. The former began from a few and gradually, by experience, instruction, and the example of others, amended ancient and barbarous laws. The latter, instituted by Christ and the apostles, had the best precepts for living in its very beginnings and did not easily make a change except for the worse.
Basil the Great, On the Holy Spirit, certainly judged that customs which flowed from tradition must be seriously guarded. I shall transcribe the passage because it too was transferred into the Decree, distinction 12, canon 5:
“Of the doctrines and institutions which have been preserved in the Church, some indeed we possess from teaching consigned to writing, while others transmitted to us from the tradition of the apostles we have received in mystery. Both possess the same force for piety. Certainly, no one furnished with even slight experience of ecclesiastical laws will contradict these things. For if we undertake imprudently to reject those things which consist not in writing but only in custom, we shall harm the Gospel, and indeed in its principal parts, or rather shall reduce the institutions themselves to a certain empty name.
“For example—to commemorate in the first place what is first and most common—who taught in writing that those who have placed their hope in the name of our Lord Jesus Christ should be marked with the figure of the cross? When we pray,
what writings taught us to turn toward the rising sun? Which of the holy Fathers left us in writing the words of invocation when the Eucharistic bread and the cup of blessing are offered? For we are not content with those things of which the apostle and the Gospel made mention, but we also say other things both before and after, as things which possess great importance for the mystery itself, instructed by teaching not written but handed down.
“We bless the water of baptism and the oil of anointing, and furthermore the person himself who is baptized—from what Scripture? Is it not from hidden and mystical tradition? What? What written discourse taught the anointing with oil itself? Whence have we received that a human being is to be immersed three times? What Scripture commanded renouncing Satan and his angels and all the remaining things whatsoever which we observe in baptism? Are they not from this teaching, not made public but secret, which our fathers guarded with quiet and altogether incurious silence? They understood well that the majesty of the mysteries is preserved by silence.”
I shall conclude with the golden maxim of Pope Nicholas to Hincmar, archbishop of Reims: “An evil custom, which is to be avoided no less than a pernicious corruption, unless it is more quickly torn out by the roots, is assumed by the wicked as a right of privileges; and transgressions and various presumptions, if they are not very swiftly suppressed, begin to be revered as laws and perpetually celebrated in the manner of privileges.” It is an oracle which is fulfilled daily.