[45] ‘ipse vero aer, qui natura est maxime frigidus, minime est expers caloris’ Cic. _N. D._ ii 10, 26; ‘aer nunquam sine igne est. detrahe illi calorem; rigescet, stabit, durabitur’ Sen. _N. Q._ iii 10, 4. [46] ‘quid autem est, quod magis credatur ex se ipso habere intentionem quam spiritus?’ Sen. _N. Q._ ii 8. Aristotle held that air was warm (Arnim ii 431). [47] ‘detrahe [aeri] calorem; transiet in humorem’ Sen. _N. Q._ iii 10, 4. [48] ‘est aliquid in aqua vitale’ _ib._ v 5, 2. [49] ‘non esse terram sine spiritu palam est ... illo dico vitali et vegeto et alente omnia. hunc nisi haberet, quomodo tot arbustis spiritum infunderet non aliunde viventibus, et tot satis?... totum hoc caelum, ... omnes hae stellae ..., hic tam prope a nobis agens cursum sol ... alimentum ex terra trahunt’ _ib._ vi 16, 1 and 2. [50] Philod. _de ira_ p. 77 Gomp. [51] ‘ex quo concluditur, calidum illud atque igneum in omni fusum esse natura’ Cic. _N. D._ ii 10, 28. [52] cap. xi, p. 38 D. [53] Schmekel, pp. 463, 4. [54] _ib._ p. 464. [55] Diog. L. vii 145 and 146; Posidonius is his general authority, but the theory of the solar eclipse he refers to Zeno. [56] ‘[lunae] tenuissimum lumen facit proximus accessus ad solem, digressus autem longissimus quisque plenissimum’ Cic. _N. D._ ii 19, 50. [57] Pliny, _Nat. hist._ ii 21. [58] Such was the calculation of Posidonius; see Mayor’s note on Cic. _N. D._ ii 36, 92. The sun’s diameter is in fact three times as large as Posidonius thought. [59] This explanation has so plausible a sound that it may not be superfluous to remark that it is scientifically valueless. [60] Cic. _N. D._ ii 20, 51. [61] ‘persuadent enim mathematici terram in medio mundo sitam ad universi caeli complexum quasi puncti instar obtinere, quod κέντρον illi vocant.’ _Tusc. disp._ i 17, 40. [62] Diog. L. vii 144 and 145. [62a] ‘ego nostris non adsentior; non enim existimo cometen subitaneum ignem sed inter aeterna opera naturae’ _N. Q._ vii 21, 1. [63] ‘omni terrarum ambitu non semel maior’ Sen. _N. Q._ vi 16, 2. [64] Ἡράκλειτος καὶ οἱ Στωϊκοὶ τρέφεσθαι τοὺς ἀστέρας ἐκ τῆς ἐπιγείου ἀναθυμιάσεως Aët. _plac._ ii 17, 4; ‘[sidera] marinis terrenisque umoribus longo intervallo extenuatis [aluntur]’ Cic. _N. D._ ii 16, 43; ‘totum hoc caelum ... halitu terrarum [sustinetur]’ Sen. _N. Q._ vi 16, 2. [65] Ar. Did. fr. 34; for the text and interpretation see Hirzel, pp. 121, 122. [66] Aët. _plac._ ii 14, 1 and 2. [67] ‘solem quoque animantem esse oportet, et quidem reliqua astra, quae oriantur in ardore caelesti, qui aether vel caelum nominatur’ Cic. _N. D._ ii 15, 41. [68] Cic. _N. D._ iii 14, 37. [69] ‘ideo enim, sicut et Posidonius et Cleanthes adfirmant, solis meatus a plaga, quae usta dicitur, non recedit, quia sub ipsa currit Oceanus’ Macrob. _Sat._ i 23, 2.