Measure for measure.
72. The question now arises, How is it that, in spite of this constant flux, things appear relatively stable? The answer of Herakleitos was that it is owing to the observance of the “measures,” in virtue of which the aggregate bulk of each form of matter in the long run remains the same, though its substance is constantly changing. Certain “measures” of the “ever-living fire” are always being kindled, while like “measures” are always going out (fr. [20]); and these measures the sun will not exceed. All things are “exchanged” for fire and fire for all things (fr. [22]), and this implies that for everything it takes, fire will give as much. “The sun will not exceed his measures” (fr. [29]).
And yet the “measures” are not to be regarded as absolutely fixed. We gather from the passage of Diogenes quoted above that Theophrastos spoke of an alternate preponderance of the bright and dark exhalations, and Aristotle speaks of Herakleitos as explaining all things by evaporation.[[382]] In particular, the alternation of day and night, summer and winter, were accounted for in this way. Now, in a passage of the pseudo-Hippokratean treatise Περὶ διαίτης which is almost certainly of Herakleitean origin,[[383]] we read of an “advance of fire and water” in connexion with day and night and the courses of the sun and moon.[[384]] In fr. [26], again, we read of fire “advancing,” and all these things seem to be intimately connected. We must therefore try to see whether there is anything in the remaining fragments that bears upon the subject.
Man
73. In studying this alternate advance of fire and water, it will be convenient to start with the microcosm. We have more definite information about the two exhalations in man than about the analogous processes in the world at large, and it would seem that Herakleitos himself explained the world by man rather than man by the world. In a well-known passage, Aristotle implies that soul is identical with the dry exhalation,[[385]] and this is fully confirmed by the fragments. Man is made up of three things, fire, water, and earth. But, just as in the macrocosm fire is identified with the one wisdom, so in the microcosm the fire alone is conscious. When it has left the body, the remainder, the mere earth and water, is altogether worthless (fr. [85]). Of course, the fire which animates man is subject to the “upward and downward path,” just as much as the fire of the world. The Περὶ διαίτης has preserved the obviously Herakleitean sentence: “All things are passing, both human and divine, upwards and downwards by exchanges.”[[386]] We are just as much in perpetual flux as anything else in the world. We are and are not the same for two consecutive instants (fr. [81]). The fire in us is perpetually becoming water, and the water earth; but, as the opposite process goes on simultaneously, we appear to remain the same.[[387]]
(a) Sleeping and waking.
74. This, however, is not all. Man is subject to a certain oscillation in his “measures” of fire and water, and this gives rise to the alternations of sleeping and waking, life and death. The locus classicus on this subject is a passage of Sextus Empiricus, which reproduces the account of the Herakleitean psychology given by Ainesidemos (Skeptic, c. 80-50 B.C.).[[388]] It is as follows (R. P. 41):—
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.
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.
(b) Life and death.