[355] Ambr. Ep. xxi. Sermo contra Aux. p. 868.
[356] Ignatius is said to have first introduced antiphonal singing at Antioch, Flavian and Diodorus to have established it there; Socr. v. 8; Theod. ii. 19. Basil refers to it as a common practice, but Ambrose is generally allowed to have introduced it to the Western Church, and on this occasion. Vide Suicer.
[357] Aug. Conf. ix. 7, and preceding books.
[358] Ambr. Ep. xxi.
[359] Ambr. Ep. xxii. Aug. Conf. ix. 7.
[360] Ambr. Ep. xl. and xli.
[361] Cod. Theod. iv. v. 4, lib. 2. De Broglie, vi. 257.
[362] Sozom. vii. 25. Theod. v. 17. Ambr. Ep. li. De Broglie, vi. 302, etc.
[363] Theod. v. 18. De Broglie, vi. 302 et seq.
[364] Sozom. vii. 15. Socr. v. 15. Ambr. Ep. lvi. Theod. v. 23.