[21] Poet. ch. 7.
[22] Diog. Lært. v. ch. i, § 20.
[23] Tuscul. quæst. bk. iv. § 13.
[24] Poet. ch. iv. 3.
[25] De aud. poetis, ch. 3.
[26] Enneads, I. bk. vi. ch. i.
[27] Enneads, loc. cit. chs. 2-9.
[28] Enneads, V. bk. viii. ch. i.
[29] Enneads, loc. cit. chs. 2-3.
[30] Phædrus, ch. 4.