The science of the laws is the slow growth of time and experience, and the advantage both of method and materials is naturally assumed by the most recent authors.
Justinian Code Published, featuring a series of excerpts selected from The History of the Decline and Fall of the Roman Empire by Edward Gibbon published in 1788.
Previously in Justinian Code Published. Now we continue.
If Caesar had achieved the reformation of the Roman law, his creative genius, enlightened by reflection and study, would have given to the world a pure and original system of jurisprudence. Whatever flattery might suggest, the Emperor of the East was afraid to establish his private judgment as the standard of equity; in the possession of legislative power, he borrowed the aid of time and opinion; and his laborious compilations are guarded by the sages and legislators of past times. Instead of a statue cast in a simple mould by the hand of an artist, the works of Justinian represent a tessellated pavement of antique and costly, but too often of incoherent, fragments. In the first year of his reign he directed the faithful Tribonian and nine learned associates to revise the ordinances of his predecessors, as they were contained, since the time of Adrian, in the Gregorian, Hermogenian, and Theodosian codes; to purge the errors and contradictions, to retrench whatever was obsolete or superfluous, and to select the wise and salutary laws best adapted to the practice of the tribunals and the use of his subjects. The work was accomplished in fourteen months; and the Twelve books or Tables, which the new decemvirs produced, might be designed to imitate the labors of their Roman predecessors.
The new Code of Justinian was honored with his name and confirmed by his royal signature: authentic transcripts were multiplied by the pens of notaries and scribes; they were transmitted to the magistrates of the European, the Asiatic, and afterward the African provinces; and the law of the empire was proclaimed on solemn festivals at the doors of churches. A more arduous operation was still behind — to extract the spirit of jurisprudence from the decisions and conjectures, the questions and disputes of the Roman civilians. Seventeen lawyers, with Tribonian at their head, were appointed by the Emperor to exercise an absolute jurisdiction over the works of their predecessors. If they had obeyed his commands in ten years, Justinian would have been satisfied with their diligence; and the rapid composition of the Digest or Pandects in three years will deserve praise or censure, according to the merit of the execution.
From the library of Tribonian they chose forty, the most eminent civilians of former times: two thousand treatises were comprised in an abridgment of fifty books; and it has been carefully re-reduced in this abstract to the moderate number of one hundred and fifty thousand. The edition of this great work was delayed a month after that of the Institutes, and it seemed reasonable that the elements should precede the digest of the Roman law. As soon as the Emperor had approved their labors, he ratified by his legislative power the speculations of these private citizens: their commentaries on the Twelve Tables, the perpetual edict, the laws of the people, and the decrees of the senate succeeded to the authority of the text; and the text was abandoned as a useless, though venerable, relic of antiquity. The Code, the Pandects, and the Institutes were declared to be the legitimate system of civil jurisprudence; they alone were admitted in the tribunals, and they alone were taught in the academies of Rome, Constantinople, and Berytus. Justinian addressed to the senate and provinces his eternal oracles; and his pride, under the mask of piety, ascribed the consummation of this great design to the support and inspiration of the Deity.
Since the Emperor declined the fame and envy of original composition, we can only require at his hands method, choice, and fidelity, the humble, though indispensable, virtues of a compiler. Among the various combinations of ideas it is difficult to assign any reasonable preference; but as the order of Justinian is different in his three works, it is possible that all may be wrong; and it is certain that two cannot be right. In the selection of ancient laws he seems to have viewed his predecessors without jealousy and with equal regard: the series could not ascend above the reign of Adrian; and the narrow distinction of paganism and Christianity, introduced by the superstition of Theodosius, had been abolished by the consent of mankind. But the jurisprudence of the Pandects is circumscribed within a period of a hundred years, from the perpetual edict to the death of Severus Alexander: the civilians who lived under the first Caesars are seldom permitted to speak, and only three names can be attributed to the age of the republic. The favorite of Justinian (it has been fiercely urged) was fearful of encountering the light of freedom and the gravity of Roman sages. Tribonian condemned to oblivion the genuine and native wisdom of Cato, the Scaevolas, and Sulpicius; while he invoked spirits more congenial to his own, the Syrians, Greeks, and Africans, who flocked to the imperial court to study Latin as a foreign tongue and jurisprudence as a lucrative profession. But the ministers of Justinian were instructed to labor, not for the curiosity of antiquarians, but for the immediate benefit of his subjects. It was their duty to select the useful and practical parts of the Roman law; and the writings of the old republicans, however curious or excellent, were no longer suited to the new system of manners, religion, and government.
Perhaps, if the preceptors and friends of Cicero were still alive, our candor would acknowledge that, except in purity of language, their intrinsic merit was excelled by the school of Papinian and Ulpian. The science of the laws is the slow growth of time and experience, and the advantage both of method and materials is naturally assumed by the most recent authors. The civilians of the reign of the Antonines had studied the works of their predecessors: their philosophic spirit had mitigated the rigor of antiquity, simplified the forms of proceeding, and emerged from the jealousy and prejudice of the rival sects.
More information here.