When Justinian I, towards the close of his life, tried to raise the sect of the Aphthartodocetae to the rank of Orthodoxy and determined to expel Patriarch Eutychius of Constantinople for his opposition, the able lawyer-ecclesiastic of Antioch, who had already distinguished himself by his great edition of the canons, was chosen to carry out the imperial will.
Following some older work which he mentions in his preface, he abandoned the historical plan of giving the decrees of each council in order and arranged them on a philosophical principle, according to their matter.
Writing to Photius I of Constantinople, Pope Nicholas I cites a harmony of the canons which includes those of Sardica, which could only be that of John.
When John came to Constantinople, he edited the Nomocanon, an abridgment of his former work, with the addition of a comparison of the imperial rescripts and civil laws (especially the Novels of Justinian) under each head.
mentions his catechism, in which he established the teaching of the consubstantial Trinity, saying that he wrote it in 568, under Emperor Justin II and that it was afterwards attacked by the impious John Philoponus.
Johann Albert Fabricius, xi, 101; xii, 146, 193, 201, 209; Evagrius Scholasticus, H. E., iv, 38, v. 13, Patrologia Graeca lxxxvi, pt.