Abstract
Prefaces are the places where authors most directly express their aims and their relationship with other texts. However, prologues to legal works have come down to us in small numbers, again due to the choices made by the compilers of Justinian's anthology. Those that have survived are located at strategic points in the Digest, such as the prologue to Ulpian's Institutiones(D., 1, 1, 1 pr.-1) on the notion of ius, or that of Modestin, who justifies the choice of writing exceptionally in Greek(D., 27, 1, 1). Alongside these rare, developed prefaces, the Digest also contains a few more synthetic and technical ones, such as those that punctuate Ulpian's commentary on the edict (e.g. D., 12, 1, 1 pr.-1). But they must have been more numerous, as confirmed by traces preserved outside the Digest. While Cicero(De orat., 2, 221-226) passed on the memory of the initia of the three books of Brutus' ius civile, in the middle of the 2nd century B.C., the oldest fully preserved preface outside the Digest is that of Maecianus'Assis distributio , a treatise written in 139 A.D. and dedicated to the young Marcus Aurelius. That Gaius' Res Cottidianae also had a prologue can be guessed from Justinian's Institutiones, which undoubtedly adopted it(I., 1, 1, 1). Jurists thus adapted the style of their prefaces to the work they were introducing, while inscribing them in a long literary tradition, as a bridge between technical knowledge and a broader cultural horizon shared with their readers.
Gaius' preface to the commentary on the Twelve Tables is the earliest transmitted by the Digest. The reflection it contains on the function of history in a legal work is sufficient to explain why it was preserved by the compilers as an introduction to the only title with historical content in Justinian's collection(D., 1, 2 : De origine iuris et omnium magistratuum et de successione prudentium). Gaius starts from two postulates: a thing is perfect because it is made up of all its parts; of all the parts, the most powerful is the beginning. These postulates can be traced back to rhetorical and philosophical sources, from Plato and Aristotle to Cicero and Quintilian. A preface was therefore called for, just as the past, the initial and decisive part of the story, was to open his commentary on the Law of the Twelve Tables. Gaius thus justifies the need to set out the beginning of the ius before the decemvirale legislation : for the jurist, history has an explanatory function.
" Facturus legum vetustarum interpretationem " : in his preface, Gaius also alludes to the preface by Livy (" Facturusne operae pretium sim si a primordio urbis res populi Romani perscripserim "), who questioned the advisability of writing a history going back to the origins of Rome, providing Gaius with the concepts and lexicon for his own reflection(principium, origo, initia), and us with the opportunity to insert a jurist's thoughts on the past of law into a wider cultural field.
