Regulæ Juris

Regulæ Juris, also spelled as Regulae - and - Iuris (Latin for Rules of Law) is a generic term for general rules or principles serving chiefly for the interpretation of canon laws.

Canonical use

In a specific sense, however, regulæ juris are certain fundamental laws in the form of axioms found in the Corpus Juris Canonici, eleven inserted by Pope Gregory IX at the end of the fifth Book of Decretals, eighty-eight by Pope Boniface VIII in the last title of Liber Sextus Decretalium.

These rules are an exposition of several laws on the same subject, conclusions or deductions, rather than principles of law drawn from constitutions or decisions, and consequently reserved to the last title of the two books mentioned, in imitation of Justinian in the "Digest" (L, l, tit. 17).

While these rules are of great importance, it must be stated that few general statements are without exception. Some of the axioms are applicable in all matters, others are confined to judicial trials, benefices, etc. As examples the following are taken from the Liber Sextus: No one can be held to the impossible (6); Time does not heal what was invalid from the beginning (18); What is not allowed to the defendant, is denied to the plaintiff (32); What one is not permitted to do in his own name, he may not do through another (47).

The Eighty-Eight by Boniface VIII

These 88 legal dicta or maxims known as De Regulis Juris were promulgated in 1298 by Boniface VIII.

1	Beneficium ecclesiasticum non potest licite sine institutione canonica obtineri.	An ecclesiastical benefice cannot be obtained licitly without canonical institution.
2	Possessor malae fidei ullo tempore non praescribit.	No prescription for a possessor of bad faith.
3	Sine possessione praescriptio non procedit.	No prescription without possession.
4	Peccatum non dimittitur nisi restituatur ablatum.	No forgiveness of sin unless there is restitution.
5	Peccati venia non datur nisi correcto.	There is no forgiveness, unless the sinner has mended his ways.
6	Nemo potest ad impossibile obligari.	No one is bound to do the impossible.
7	Privilegium personale personam sequitur et extinguitur cum persona.	A personal privilege follows the person; it comes to an end when the person dies.
8	Semel malum semper praesumitur esse malum.	Who does wrong once is presumed to be a wrongdoer always. (Who does wrong out of malice once, is presumed to be a malicious person).
9	Ratum quis habere non potest quod eius nomine non est gestum.	No one can ratify what was not done in his name and through his mandate. (No one can ratify what he did not mandate to do).
10	Ratihabitionem retrotrahi et mandato non est dubium comparari.	Ratification can be retroactive; it can be equivalent to a mandate.
11	Cum sunt partium iura obscura reo fovendum est potius quam actori.	When the rights of the parties are obscure the accused should be favored over the accuser.
12	In iudicii non est acceptio personarum habenda.	In judicial procedure no special favor is given to any person. (All are equal before a court).
13	Ignorantia facti non iurii excusat.	Ignorance of a fact constitutes an excuse; ignorance of law does not.
14	Cum quis in ius alterius succedit iustam ignorantiae causam habere censetur.	When someone succeeds into the rights of another, he is assumed to have a good reason to plead ignorance.
15	Odia restringi et favores convenit ampliari.	Whatever is odious ought to be restricted; whatever is favorable ought to be extended.
16	Decet beneficium concessum a Principe esse mansurum.	It is fitting that a benefice given by a prince should stay. (A favor once granted by the superior should have stability).
17	Indultum a iure beneficium non est alicui auferendum.	When the law grants a benefice, no one should take it away. (A favor granted by a law should not be taken away by anyone).
18	Non firmatur tractu temporis quoad ab initio non subsistit.	The passage of time will not remedy a situation that had no legal foundation. (What was illegal in the beginning will not become legal with the passage of time)
19	Non est sine culpa qui rei quae ad se non pertinet se immiscet.	If someone interferes in a business that is not his own, he is not without fault. (To interfere with the business of a third party is to accept liability).
20	Nullus pluribus uti defensionibus prohibetur.	No one is forbidden to use several defenses.
21	Quod semel placuit amplius displicere non potest.	What was approved once cannot be disapproved later.
22	Non debet aliquis alterius odio praegravari.	No one must be judged unfavorably because someone hates him. (In judicial procedure emotional prejudice must be excluded.)
23	Sine culpa, nisi subsit causa non est aliquis puniendus.	Who is not culpable, should not be punished; but disadvantages may be imposed on him if there is a permanent cause.
24	Quod quis mandato facit iudicis, dolo facere non videtur, cum habeat parere necesse.	When someone does something by the order of a judge; he cannot act out of malice since he must obey the judge.
25	Mora sua cuilibet nociva est.	Who delays harms himself.
26	Ea quae fiunt a iudice si ad eius non spectant officium non subsistunt.	Whatever a judge does outside the scope of his office has no legal force.
27	Scienti et consentienti non fit iniuria neque dolus.	Who knows and agrees has no cause to complain of injury or malice.
28	Quae a iure communi exorbitant nequaquam ad consequentiam sunt tradenda.	Whatever is beyond the scope of common law must not be further extended.
29	Quod omnes tangit debet ab omnibus probari.	What concerns all must be approved by all.
30	In obscuris minimum est sequendum.	When the meaning is obscure, the obligation is reduced to the minimum significance
31	Eum qui certus est certiorari ulterius non oportet.	If someone knows with certainty, there is no need to inform him further.
32	Non licet actori quod reo licitum non exsistit.	The accuser is not permitted to do what is not permitted to the accused.
33	Mutare quis consilium non potest in alterius detrimentum.	No one can change his mind (intention) at the expense of another.
34	Generi per speciem derogatur.	The particular takes precedence over the general. (The diocesan laws, unless it is contrary, take precedence over universal laws.)
35	Plus semper in se continet quod est minus.	The more includes the less. (If one can do a greater thing, the lesser can certainly be done.)
36	Pro possessore habetur qui dolo desiit possidere.	If someone abandoned possessions maliciously, he is held as the possessor. (No one can free himself from the duties or liabilities of the possessor by abandoning maliciously the state of possession).
37	Utile per inutile non debet vitiari.	The useful must not be vitiated by the useless.
38	Ex eo non debet quis fructum consequi quod nisus extitit impugnare.	No one should profit from something (law, document, fact), that he himself contested previously.
39	Cum quid prohibetur, prohibentur omnia quae sequuntur ex illo.	When something is forbidden, everything is forbidden that follows from it.
40	Pluralis locutio duorum numero est contenta.	Any speech in plural refers to two (at least).
41	Imputari ei non debet per quem non stat si non fiat quod per eum fuerat faciendum.	No one should be blamed for not having done what he had to do, when the possibility of doing it did not depend on him.
42	Accessorium naturam sequi congruit principalis.	The accessory follows the nature of the principal.
43	Qui tacit consentire videtur.	Who keeps silent seems to (is deemed to) consent.
44	Is qui tacit non fatetur, sed nec utique negare videtur.	Who keeps silent does not confess anything, but he does not deny anything either.
45	Inspicimus in obscuris quod est verisimilius, vel quod plerumque fieri consuevit.	In obscure things we should hold to what is more likely or what is more customary.
46	Is qui in ius succedit alterius, eo iure quo ille uti debebit.	When someone succeeds into the rights of another, he has the same rights as the other one did.
47	Praesumitur ignorantia ubi scientia non probatur.	Ignorance is presumed when knowledge is not proved.
48	Locupletari non debet aliquis cum alterius iniuria vel iactura.	No one should profit from the injury or failure of another one.
49	In poenis benignior est interpretatio facienda.	In matters of penalty a more benign interpretation is the right one.
50	Actus legitimi conditionem non recipiunt neque diem.	Certain legal acts cannot be restricted by the imposition of a condition or of a time limit.
51	Semel Deo dicatum non est ad usus humanos ulterius transferendum.	Once given to God it should not be transferred to the use of man.
52	Non praestat impedimentum quod de iure non sortitur effectum.	An act when null and void in the beginning cannot be a legal obstacle later.
53	Cui licet quod est plus licet utique quod est minus.	Who can do more, can do less.
54	Qui prior est tempore potior est iure.	The one first in time has a stronger right.
55	Qui sentit onus sentire debet commodum et contra.	Who feels the burden should feel the comfort as well. (Burden and relief, advantages and disadvantages originating in the same law or legal situation must go together).
56	In re communi potior est conditio prohibentis.	When rights are held in common, the negative vote outweighs all others. (I.e. for a decision unanimity is necessary).
57	Contra eum qui legem dicere potuit apertius est interpretatio facienda.	In case of doubt all interpretation should go against the one who should have spoken clearly.
58	Non est obligatorium contra bonos mores praestitum iuramentum.	An oath against good morals does not bind.
59	Dolo facit qui petit quod restituere oportet eumdem.	To ask immediately for what must be restituted is to reveal malicious intention.
60	Non est in mora qui potest exceptione legitima se tueri.	Someone who can defend himself with a legitimate exception should not be faulted for delay. (I.e. he would be excused anyway).
61	Quod ob gratiam alicuius conceditur non est in eius dispendium retorquendum.	Whatever is given to the benefit of another should not be turned to his disadvantage.
62	Nullus est consilio, dummodo fraudolentum non fuerit obligatur.	No liability arises from advice given provided it was not fraudulent.
63	Exceptionem obiiciens non videtur de intentione adversarii confiteri.	To move an exception is not the admission of the accusation. (The accused may use even contradictory exceptions).
64	Quae contra ius fiunt, debent utique pro infectis haberi.	Whatever is done against the law should be held null and void (should be held as not done, vitiated).
65	In pari delicto et causa potior est conditio possidentis.	All things being equal, the possessor has the stronger right.
66	Cum non stat per eum ad quem pertinet quominus conditio impleatur, haberi debet perinde ac si impleta fuisset.	When a person is bound to fulfill a condition, but the possibility of doing so does not depend on him, the condition should be deemed fulfilled.
67	Quod alicui suo non licet nomine nec alieno licebit.	When someone is forbidden to do something, he cannot escape the prohibition by doing it for someone else.
68	Potest quis per alium quod potest facere per seipsum.	Whatever someone can do by himself, he can do it by another (unless the power to act cannot be delegated).
69	In malis promissis fides non expedit observari.	A promise to do wrong does not generate a duty to be faithful.
70	In alternativis debitoris est electio et sufficit alterum adimpleri.	In case of alternative duties the debtor is entitled to choose one of them; by doing one he can satisfy all obligations.
71	Qui ad agendum admittitur est ad excipiendum multo magis admittendus.	Whoever is entitled to sue is even more entitled to raise an exception.
72	Qui facit per alium est perinde ac si faciat per seipsum.	When someone acts through another (a representative, a deputy, an agent) he is as much responsible as if he did it himself.
73	Factum legitimum retrotrahi non debet, licet casus postea eveniat a quo non potuit inchoari.	A valid legal transaction cannot be annulled because of an invalidating factor that came into being afterwards.
74	Quod alicui gratiose conceditur trahi non debet ab aliis in exemplum.	A gracious concession to someone should not be quoted by another as a precedent.
75	Frustra sibi fidem quis postulat ab eo servari, cui fidem a se praestitam servare recusat.	No one should ask for faithful compliance by another when he is not faithful in his duty towards the other. (He who breeches faith toward his partner, is not entitled to ask him to be faithful).
76	Delictum personae non debet in detrimentum Ecclesiae redundare.	The crime of a person should not be harm (cause damage) to the Church. (The Church should not: suffer because of personal wrongdoing.)
77	Rationi congruit ut succedat in onere qui substituitur in honore.	It is fair that when someone succeeds another one in an honorable position, he should take the burden that goes with.
78	In argumentum trahi nequeunt quae propter necessitatem aliquando sunt concessa.	When a concession is made out of necessity it cannot serve as a legitimate precedent.
79	Nemo potest plus iuris transferre in alium quam sibi ipsi competere diagnoscatur.	No one gives more right to another than what he has.
80	In toto partem non est dubium contineri.	No doubt, the part is contained in the whole.
81	In generali concessione veniunt ea quae quis esset verisimiliter in specie concessurus.	A general grant does not contain those particular concessions that the superior was never likely to give.
82	Qui contra ius mercatur bonam fidem praesumitur non habere.	Those who bargain against the law are presumed to lack good faith.
83	Bona fides non patitur ut semel exactum iterum exigatur.	To try to exact the same duty twice is against good faith.
84	Cum quid una vita proibetur alicui ad id alia non debet admitti.	Once forbidden, it is forbidden in every way.
85	Contractus ex conventione legem accipere diagnoscuntur.	Contracts make law for themselves.
86	Damnum quod quis sua culpa sentit sibi debet non aliis imputare.	If someone does wrong, he should blame himself for the harm that he suffers.
87	Infamibus portae non pateant dignitatum.	Dignities are closed to persons of bad reputation.
88	Certum est quod is committit in lege, qui legis verbum complectens, contra legis nititur voluntatem.	Those who comply with the letter of the law but against the intention of the law, are really against the law.

Given in Rome by St. Peter's on the Fifth Day of the Nones of March in the Fourth year of our Pontificate—Boniface VIII

References

• This article incorporates text from a publication now in the public domain: Catholic Church; Pope Boniface VIII (1881) [1298]. "De regulis iuris". In Friedberg, Emil; Richter, Aemilius Ludwig. Corpus iuris canonici (in Latin) 2 (Lipsiensis secundae ed.). Lipsiae: Bernhardi Tauchnitz. cols. 1122–1124. OCLC 693947940.
•  This article incorporates text from a publication now in the public domain: Meehan, Andrew (1911). "Regulæ Juris". In Herbermann, Charles. Catholic Encyclopedia 12. New York: Robert Appleton.