three years, Tribonian calculating that he had reduced nearly 2000 rolls containing more than 3,000,000 lines into a Codex of about 150,000 lines. Justinian called this book Digesta or Pandectae and directed that it should take effect as law from 3 December 533. Its somewhat irrational distribution into seven parts and fifty books was probably due to a superstitious regard to the mysterious efficacy of certain numbers. The really important division is into titles, of which there are 432.
From reverence to the old lawyers, he directed that the name of the writer and work from which an extract was taken should be placed at the commencement of it, and he had a list of the works used placed before the Digest. This list requires some correction. There were used between 200 and 300 treatises of about 40 authors, some of the treatises being very voluminous, so that over 1600 rolls were put under contribution. Over 95 per cent. of the Digest was from books written between the reigns of Trajan and Alexander Severus. Two works by Ulpian supply about one-third of the Digest: sixteen works by eight authors form nearly two-thirds: twice this number of books supply four-fifths. From some treatises only a single extract was taken. Tribonian's large library supplied many books not known even to the learned. Many were read through without anything suitable for extraction being found.
The plan which Tribonian devised appears to have been to divide the commission into three parts and give each committee an appropriate share of the books to be examined. Ulpian's and Paul's Commentaries and other comprehensive works were taken as the fullest exposition of current law and made the foundation. They were compared with one another and with other treatises of the same subject-matter; antiquated law and expressions were cut out or altered, contradictions removed, and the appropriate passages extracted and arranged under the titles to which they severally belonged. The titles were, as Justinian directed, mainly such as appeared in the Praetor's Edict or in his own code. The extracts made by the committee which had furnished the most matter for the title were put first, and the others followed, with little or no attempt to form an orderly exposition of the subject. What connexion of thought between the extracts is found comes mainly from the treatise taken as the foundation. There is no attempt at fusing the matter of text-books and giving a scientific result, nor even of making a thorough and skilful mosaic of the pieces extracted. The work under each title is simply the result of taking strings of extracts from the selected treatises, arranging them partly in one line and partly in parallel lines, and then as it were squeezing them together so as to leave only what is practical, with no more repetition than is requisite for clearness. This process done by each committee would be to some extent repeated when the contributions of the three committees came to be combined. For special reasons
