St. Augustine, perhaps De Trinitate, XII, 14 (PL 42:1010); or Epist. CXLVII, ad Paulinam, 13 (PL 33:610). Cf. Epist. CXX, ad Consentium, I (PL 33:454).
In q. 12, a. 3, reply.
Pseudo-Dionysius, De caelesti hierarchia, IV (PG 3:179).
St. Augustine, De Trinitate, III, 11 (PL 42:882, 886).
Ibid., III, 4 (PL 42:873).
In q. 12, a. 6, answer to the twelfth difficulty.