“Cold warms up, warm cools off, moist parches, dry dampens” (Kahn, 49)
“Cold things become warm, a warm thing becomes cold; a moist thing becomes dry, a parched thing becomes moist.” (Robison, 126; cp. S, 126)
Various points are important here.
1) The two translations of this differ in very important ways. Robinson’s translation points to an underlying substance, or of various substances — “things” that cool, warm, are moist but can become dry. Kahn’s translation does not require the underlying identity of something that undergoes a change in qualities. It is more compatible with the reading of Heraclitus as the philosopher of radical flux. If the flux is radical enough, there is no underlying substance, no underlying thing preserved through time that undergoes changes, being at one time cold, at another warm, at one time moist, at another dry. As a price for aligning with radical flux, Kahn’s translation anthropomorphizes or vitalizes the qualities under discussion: the “cold” itself, not the cold thing “warms up.” Coldness, warmness, moistness, dryness — they all do something. They move from what they are into their opposite.
2) Heraclitus’ comments here are not unique to him. Rather, Heraclitus is seen as expressing the view of the complimentarity of opposites that we find in the Meletic philosophers from Anaxagoras onward and eventually incorporated by Aristotle. Heraclitus is a philosopher of flux. But he sees the logos involved in a process of change as complimentary oppositions pass from one into another. The change, though, has a certain rational character and regularity to it. This is why, as Heraclitus says in other places, “the sun will not transgress its measure” (F 44): The seasons have a natural regularity as does the course of the sun in its daily cycle. A similar regularity occurs as fire turns to air, which turns to earth, and so on (see the comment to Fragment 41).
In Fragment 49, under discussion here, Heraclitus again speaks of the regularity of change. But his focus is not on the four elements that exist in a complimentary opposition — earth, air, water, fire. Instead, here he speaks of elemental oppositions in terms of experience. We experience the cold becoming warm, the dry becoming moist. This dovetails into a third point.
3) More than a few of Heraclitus’ fragments relate ideas not from a third-person perspective of natural philosophy but from a first-person perspective of experience. Compare this fragment to Heraclitus’ statement that “the sun’s breadth is the size of a foot.” Suspending depth perception in a move similar to a Husserlian bracketing, we can have an experience of the sun as that size (see Fragment 47). We would do well to consider that Heraclitus is not only a natural philosopher, proposing basic theories of nature, such as we have explored in his views on celestial cycles. Rather, he is also an observer of the human mind, an observer of observations, of how we perceive the world around us. Here, the point is that even from the perspective of first-person experience, we see dialectic, complimentarity of opposites.