The Navel, Reflections on the composition of the Quarta pars Digestorum

Abstract

In an earlier edition of Tijdschrift voor Rechtsgeschiedenis we have contended that Justinian’s Digest was composed on the basis of Ulpian’s Libri ad Edictum and the peculiarities and special exigencies of the legal curriculum. It was also contended that the distribution of the fifty books over the seven partes of the Digest was based on a mathematical formula, complicated by the fact that Justinian (Tribonian) had decided to assign four books to the first pars (Ta prota) and 36 to the first five partes together according to ‘the nature and science of numbers’ (natura et ars numerorum). This article offers some additional arguments supporting our thesis and concentrates on the composition of the quarta pars Digestorum, designated by Justinian himself as ‘The Navel’ (Umbilicus) of the entire composition. The hypothesis is that Tribonian composed the quarta pars Digestorum as a microcosm of the Digest as a whole and that he has been ‘juggling with numbers’ within the composition of ‘The Navel’ as he has ostensibly done in the composition of the Digest as a whole.