The natural philosopher is of opinion that what surrounds us[389] is rational and endowed with consciousness. According to Herakleitos, when we draw in this divine reason by means of respiration, we become rational. In sleep we forget, but at our waking we become conscious once more. For in sleep, when the openings of the senses close, the mind which is in us is cut off from contact with that which surrounds us, and only our connexion with it by means of respiration is preserved as a sort of root (from which the rest may spring again); and, when it is thus separated, it loses the power of memory that it had before. When we awake again, however, it looks out through the openings of the senses, as if through windows, and coming together with the surrounding mind, it assumes the power of reason. Just, then, as embers, when they are brought near the the fire, change and become red-hot, and go out when they are taken away from it again, so does the portion of the surrounding mind which sojourns in our body become irrational when it is cut off, and so does it become of like nature to the whole when contact is established through the greatest number of openings. Footnote 388: Sextus quotes “Ainesidemos according to Herakleitos.” Natorp holds (_Forschungen_, p. 78) that Ainesidemos really did combine Herakleiteanism with Skepticism. Diels, on the other hand (_Dox._ pp. 210, 211), insists that Ainesidemos only gave an account of the theories of Herakleitos. This controversy does not affect the use we make of the passage. Footnote 389: τὸ περιέχον ἡμᾶς, opposed to but parallel with τὸ περιέχον τὸν κόσμον. In this passage there is obviously a very large admixture of later phraseology and of later ideas. In particular, the identification of “that which surrounds us” with the air cannot be Herakleitean; for Herakleitos can have known nothing of air, which in his day was regarded as a form of water (§ 27). The reference to the pores or openings of the senses is probably foreign to him also; for the theory of pores is due to Alkmaion (§ 96). Lastly, the distinction between mind and body is far too sharply drawn. On the other hand, the important rôle assigned to respiration may very well be Herakleitean; for we have met with it already in Anaximenes. And we can hardly doubt that the striking simile of the embers which glow when they are brought near the fire is genuine (cf. fr. 77). The true Herakleitean doctrine doubtless was, that sleep was produced by the encroachment of moist, dark exhalations from the water in the body, which cause the fire to burn low. In sleep, we lose contact with the fire in the world which is common to all, and retire to a world of our own (fr. 95). In a soul where the fire and water are evenly balanced, the equilibrium is restored in the morning by an equal advance of the bright exhalation. [Sidenote: (_b_) Life and death.]