Note 40 — Chapter VI · THE STUDY OF NATURE. FUNDAMENTAL POSITIONS.

Cic. N. D. ii. 9, 23 (conf. iii. 14, 35), gives it apparently as the view of Cleanthes, who alone is mentioned, 9, 24. All living things, plants, and animals, exist by heat: nam omne quod est calidum et igneum cietur et agitur motu suo. Digestion and circulation are the result of heat: ex quo intelligi debet, eam caloris naturam vim habere in se vitalem per omnem mundum pertinentem. Moreover: omnes partes mundi … calore fultæ sustinentur. There must be fire in earth and stones, else it could not be extracted therefrom. Water, especially fresh spring water, is warm, more particularly in winter, and as motion warms us, so the roll of the waves does the sea. From water likewise as it evaporates, air derives its heat.… Jam vero reliqua quarta pars mundi, ea et ipsa tota natura fervida est, et cæteris naturis omnibus salutarem impertit et vitalem calorem. Ex quo concluditur, cum omnes mundi partes sustineantur calore, mundum etiam ipsum simili parique natura in tanta diuturnitate servari: eoque magis quod intelligi debet, calidum illum atque igneum ita in omni fusum esse natura, ut in eo insit procreandi vis, &c. ↑