Aristotle, De divinatione per somnum, I (462b 23).
Plato, Timaeus, 30B.
Pseudo-Dionysius, De divinis nominibus, IV (PG 4:698-99).
Moses Maimonides, The Guide for the Perplexed, II, 36 (FR 226); II, 40 (FR 234).
Glossa ordinaria, super Matt. 7:15 (V:29r).