During this golden age of Roman jurisprudence, many commentaries were written on the Twelve Tables, the Perpetual Edict, the Laws of the People, and the Decrees of the Senate, as well as a vast mass of treatises on every department of the law, most of which have perished. The Institutes of Gaius, which have reached us nearly in their original form, are the most valuable which remain, and have thrown great light on some important branches previously involved in obscurity. Their use in explaining the Institutes of Justinian, is spoken of very highly by Mackenzie, since the latter are mainly founded on the long lost work of Gaius. A treatise of Ulpian, preserved in the Vatican, entitled "Tituli ex corpore Ulpiani" also contains valuable information, as well as the "Receptae Sententiae" of Julius Paulus, his great contemporary, both of which works, as well as others of inferior importance, were lately published at Rome by Dr. Gneist, called "Corpus Juris Romani Antejustinianii." [Footnote: Mackenzie, p. 16.] The great lawyers who flourished from Trajan to Alexander Severus, like Gaius, Ulpian, Paulus, Papinian, and Modestinus, had no successors who can be compared with them, and their works became standard authorities in the courts of law.
After the death of Alexander Severus no great accession was made to Roman law, until Theodosius II. caused the constitutions, from Constantine to his own time, to be collected and arranged in sixteen books. This was called the Theodosian Code, which in the West was held in high esteem, although superseded shortly after in the East by the Justinian Code.
[Sidenote: Justinian labors.]
To Justinian belongs the immortal glory of reforming the jurisprudence of the Romans. "In the space of ten centuries," says Gibbon, "the infinite variety of laws and legal opinions had filled many thousand volumes, which no fortune could purchase, and no capacity could digest. Books could not easily be found and the judges, poor in the midst of riches, were reduced to the exercise of their illiterate discretion." [Footnote: Gibbon, ch. 44.] Justinian determined to unite in one body all the rules of law, whatever may have been their origin, and in the year 528, appointed ten jurisconsults, among whom was the celebrated Tribonian, to select and arrange the imperial constitutions, leaving out what was obsolete or useless or contradictory, and to make such alterations as the circumstances required. This was called the Code, divided into twelve books, and comprising the constitutions from Hadrian to Justinian. This was published in fourteen months after it was undertaken.
[Sidenote: Tribonian.]
[Sidenote: The code of Pandects.]
Justinian authorized Tribonian, then quaestor, "vir magnificus magisteria dignitate inter agentes decoratus," for great titles were now given to the officers of the crown, to prepare, with the assistance of seventeen associates, a collection of extracts from the writings of the most eminent jurists, so as to form a body of law for the government of the empire, with power to select and omit and alter; and this immense work was done in three years, and published under the title of Digest or Pandects. "All the judicial learning of former times," says Lord Mackenzie, "was laid under contribution by Tribonian and his colleagues. Selections from the works of thirty-nine of the ablest lawyers, scattered over two thousand separate treatises, were collected in one volume; and care was taken to inform posterity that three millions of lines were abridged and reduced, in these extracts, to the modest number of one hundred and fifty thousand. Among the selected jurists, only three names belonged to the age of the republic; the civilians who flourished under the first emperors are seldom appealed to; so that most of the writers, whose works have contributed to the Pandects, lived within a period of one hundred years. More than a third of the whole Pandects is from Ulpian, and next to him, the principal writers are Paulus, Papinian, Salvius Julianus, Pomponius, Q. Cervidius Scaevola, and Gaius. Though the variety of subjects is immense, the Digest has no claims to scientific arrangement. It is a vast cyclopedia of heterogeneous law badly arranged; every thing is there, but every thing is not in its proper place." [Footnote: Mackenzie, p. 25.]
[Sidenote: The Institutes.]
But neither the Digest nor the Code was adapted to elementary instruction. It was necessary to prepare a treatise on the principles of Roman law. This was entrusted to Tribonian, and two professors, Theophilus and Dorotheus. It is probable that Tribonian merely superintended the work, which was founded chiefly on the Institutes of Gains, and was divided into four books, and has been universally admired for its method and elegant precision. It was intended merely as an introduction to the Pandects and the Code.
[Sidenote: The Novels of Justinian.]