Aristotle, Ethica Nicomachea, I, 13 (1102b 23 ff.).
Boethius, De consolatione philosophiae, V, prosa 4 (PL 63:849).
Pseudo-Dionysius, De caelesti hierarchia, XII (PG 3:291).
Boethius, Commentaria in Porphyrium, I (Mox de generibus), (PL 64:85).
See q. 1, a. 4, above.
Aristotle, Metaph., {Z}, 8 (1034a 5); Z, 10 (1035b 28); Z, 11 (1037a 5).
Aristotle, De anima, III, 11 (434a 16).