"The locus classicus on this... is... Sextus Empiricus, which reproduces the account of the Herakleitean psychology given by Ainesidemos... (R. P. 41):— The natural philosopher is of opinion that what surrounds us is rational and endowed with consciousness. According to Herakleitos, when we draw in this divine reason by... respiration, we become rational. In sleep we forget, but at our waking we become conscious once more. For in sleep... the mind... is cut off from... that which surrounds us, and only our connexion... by... respiration is preserved as a... root (from which the rest may spring again); and, when... thus separated, it loses the power of memory... When we awake again... 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... as embers... brought near the fire, change and become red-hot, and go out when they are taken away... so does the portion of... mind... become irrational when... cut off, and... become of like nature to the whole... through the greatest number of openings. In this passage there is... a... large admixture of later... ideas. In particular... identification of "that which surrounds us" with the air... for Herakleitos can have known nothing of air, which in his day was regarded as a form of water... The reference to the pores or openings of the senses is probably foreign... for the theory of pores is due to Alkmaion. ...[T]he distinction between mind and body is far too sharply drawn. ...[T]he important rôle assigned to respiration may very well be Herakleitean; for we ... met with it ...in Anaximenes. ...[T]he striking simile of the embers which glow when ...near the fire is genuine (cf. fr. 77)."