This volume contains the first critical edition of the last three books (four to six) of Augustine’s Unfinished Work against Julian of Eclanum written in response to Julian’s eight books ‘To Florus’. Since the Bishop of Hippo replies paragraph by paragraph to Julian’s work, the first six of them are preserved in their entirety. The edition of books one to three has been published in 1974 (CSEL 85/1, ed. M. Zelzer).