In mediaeval university documents the Digest is frequently mentioned in three divisions, which probably indicate three separate instalments in which the MS. of the work was brought to Bologna in the eleventh and twelfth centuries: the Old Digest (Digestum Vetus) Bks. I-XXIV, title ii, Infortiatum Bks. XXIV, title iii-XXXVIII, title iii, and New Digest (Digestum Novum) Bks. XXXVIII, title iv-L. The meaning of the term Infortiatum is uncertain.
This distinction between the various parts of the Digest is purely arbitrary…. The division must have originated in an accidental separation of some archetypal MS.[27]
(3) The Institutes, in four books, an elementary text-book for students. The purpose of the book was to afford a simple, clear, and trustworthy introduction to the study of law, and to economize the student's time:
When we had arranged and brought into perfect harmony the hitherto confused mass of imperial constitutions (i.e. the Code), we then extended our care to the vast volumes of ancient law; and, sailing as it were across the mid ocean, have now completed, through the favour of heaven, a work that once seemed beyond hope (i.e. the Digest).
When by the blessing of God this task was accomplished, we summoned the most eminent Tribonian, master and ex-quaestor of our palace, together with the illustrious Theophilus and Dorotheus, professors of law, all of whom have on many occasions proved to us their ability, legal knowledge, and obedience to our orders; and we have specially charged them to compose, under our authority and advice, Institutes, so that you may no more learn the first elements of law from old and erroneous sources, but apprehend them by the clear light of imperial wisdom; and that your minds and ears may receive nothing that is useless or misplaced, but only what obtains in actual practice. So that, whereas, formerly, the junior students could scarcely, after three years' study, read the imperial constitutions, you may now commence your studies by reading them, you who have been thought worthy of an honour and a happiness so great that the first and last lessons in the knowledge of the law should issue for you from the mouth of the emperor.
When, therefore, by the assistance of the same eminent person Tribonian and that of other illustrious and learned men, we had compiled the fifty books, called Digests or Pandects, in which is collected the whole ancient law, we directed that these Institutes should be divided into four books, which might serve as the first elements of the whole science of law.
In these books a brief exposition is given of the ancient laws, and of those also, which, overshadowed by disuse, have been again brought to light by our imperial authority.
These four books of Institutes thus compiled, from all the Institutes left us by the ancients, and chiefly from the commentaries of our Gaius, both in his Institutes and in his work on daily affairs, and also from many other commentaries, were presented to us by the three learned men we have above named. We have read and examined them and have accorded to them all the force of our constitutions.
Receive, therefore, with eagerness, and study with cheerful diligence, these our laws, and show yourselves persons of such learning that you may conceive the flattering hope of yourselves being able, when your course of legal study is completed, to govern our empire in the different portions that may be entrusted to your care.
Given at Constantinople on the eleventh day of the calends of
December, in the third consulate of the Emperor Justinian, ever
August (533)[28]