Digestorum libri
Ex libro LXXXIV
Dig. 1,3,32Iulianus libro LXXXIIII digestorum. De quibus causis scriptis legibus non utimur, id custodiri oportet, quod moribus et consuetudine inductum est: et si qua in re hoc deficeret, tunc quod proximum et consequens ei est: si nec id quidem appareat, tunc ius, quo urbs Roma utitur, servari oportet. 1Inveterata consuetudo pro lege non immerito custoditur, et hoc est ius quod dicitur moribus constitutum. nam cum ipsae leges nulla alia ex causa nos teneant, quam quod iudicio populi receptae sunt, merito et ea, quae sine ullo scripto populus probavit, tenebunt omnes: nam quid interest suffragio populus voluntatem suam declaret an rebus ipsis et factis? quare rectissime etiam illud receptum est, ut leges non solum suffragio legis latoris, sed etiam tacito consensu omnium per desuetudinem abrogentur.
Julianus, Digest, Book XCIV. In cases where there are no written laws, that should be observed which has been established by usage and custom, and if anything is lacking therein, then whatever is nearest to, and resulting from it should be observed; and if even this does not exist, then the law which is used by the City of Rome must be followed. 1An ancient custom is not improperly observed as a law (and this is what is called law established by usage). For as the laws themselves restrain us for no other reason than because they are accepted by the judgment of the people—for it is but proper that what the people have approved without being written should bind all persons—for what difference does it make whether the people have manifested their will by vote, or by acts and deeds? Wherefore the rule has also been most justly adopted that laws shall be abrogated not only by the vote of the legislator, but also through disuse by the silent consent of all.