[ULPIANUS libro tertio ad edictum. ] §2.2.1.prHoc edictum summam habet aequitatem, et sine cuiusquam indignatione iusta: quis enim aspernabitur idem ius sibi dici, quod ipse aliis dixit uel dici effecit? ‘Qui magistratum potestatemue habebit, si quid in aliquem noui iuris statuerit, ipse quandoque aduersario postulante eodem iure uti debet.
[ULPIAN, on the Edict, Book III.] This edict possesses the highest equity, and is free from any person's just indignation; for who will reject that the same law be applied to himself which he himself applied to others or caused to be applied? "Whoever holds a magistracy or power, if he establishes any new law against another, must himself eventually submit to the same law when his adversary requests it.
si quis apud eum, qui magistratum potestatemque habebit, aliquid noui iuris optinuerit, quandoque postea aduersario eius postulante eodem iure aduersus eum decernetur': scilicet ut quod ipse quis in alterius persona aequum esse credidisset, id in ipsius quoque persona ualere patiatur.
If anyone obtains a new law before one who holds a magistracy and power, it shall eventually afterwards, upon the request of his adversary, be decreed against him under the same law": namely, that he should allow that which he himself had believed to be equitable in the case of another to be valid in his own case as well.
§2.2.1.1Haec autem uerba: 'quod statuerit qui iurisdictioni praeest' cum effectu accipimus, non uerbo tenus: et ideo si, cum uellet statuere, prohibitus sit nec effectum decretum habuit, cessat edictum.
Moreover, we interpret these words: "what he who presides over jurisdiction has established" as referring to an actual effect, not merely literally; and therefore if, when he wished to establish it, he was prevented and the decree had no effect, the edict does not apply.
nam statuit uerbum rem perfectam significat et consummatam iniuriam, non coeptam.
For the word "established" (statuit) signifies a completed matter and a consummated wrong, not one merely begun.
et ideo si inter eos quis dixerit ius, inter quos iurisdictionem non habuit, quoniam pro nullo hoc habetur nec est ulla sententia, cessare edictum putamus: quid enim offuit conatus, cum iniuria nullum habuerit effectum?
And therefore, if anyone should administer justice between those over whom he has no jurisdiction, since this is held as null and there is no judgment at all, we think the edict does not apply; for how did the attempt do harm, when the wrong had no effect?