Note 12 (p. 22).
There is no snare in which the feet of a modern student of ancient lore, are more easily entangled, than that which is spread by the similarity of the language of antiquity to modern modes of expression. I do not presume to interpret the obscurest of Greek philosophers; all I wish is to point out, that his words, in the sense accepted by competent interpreters, fit modern ideas singularly well.
So far as the general theory of evolution goes there is no difficulty. The aphorism about the river; the figure of the child playing on the shore; the kingship and fatherhood of strife seem decisive. The ὁδὸς ἄνω κάτω μίη expresses, with singular aptness, the cyclical aspect of the one process of organic evolution in individual plants and animals; yet it may be a question whether the Heracleitean strife included any distinct conception of the struggle for existence. Again, it is tempting to compare the part played by the Heracleitean 'fire' with that ascribed by the moderns to heat, or rather to that cause of motion of which heat is one expression; and a little ingenuity might find a foreshadowing of the doctrine of the conservation of energy, in the saying that all the things are changed into fire and fire into all things, as gold into goods and goods into gold.
Note 13 (p. 23).
Pope's lines in the 'Essay on Man.' (Ep. i., 267—8.)
"All are but parts of one stupendous whole,
Whose body Nature is, and God the soul,"
simply paraphrase Seneca's "quem in hoc mundo locum deus obtinet, hunc in homine animus: quod est illic materia, id nobis corpus est."—(Ep. lxv. 24); which again is a Latin version of the old Stoical doctrine, εἰς ἅπαν τοῦ κόσμου μέρος διήκει ὁ νοῦς, καθάπερ ἀφ' ἡμῶν ἡ ψυχή.
So far as testimony for the universality of what ordinary people call 'evil,' goes, there is nothing better than the writings of the Stoics themselves. They might serve as a storehouse for the epigrams of the ultra-pessimists. Heracleitus (circa 500 B.C.) says just as hard things about ordinary humanity as his disciples
