“The way up and down is one and the same.” (Kahn 103 and S 60; cp. R, D 60)
This is one of various fragments in Heraclitus that expresses a definitional truth. Literally, if it is five miles up a road, it is also five miles back down it; and anywhere up or down a particular road one finds oneself in the same spot going up and one will coming down. Related to this, the fragment can be seen to emphasize perspectivism. One can traverse along the same road, but whether one is going up or down it depends on where one sets out from on the road and where one is heading on it. This establishes one’s perspective.
Among fragments emphasizing Heraclitus’ perspectivism is F 70 (D61): “Sea-(water)…is very pure and very foul water — for fish drinkable and life-sustaining, for people undrinkable and lethal” (R 61). Or compare F 103 (D99): “In the case of a circle[‘s circumference] beginning and end are common.”
Kahn, leaning on ancient interpretations from Theophrastus (D.L. IX.8-9) and Plotinus (LII-LII (D. 84A-B), emphasizes the possibility of interpreting the text as describing elemental and psychological processes. This explains his placement of the fragment here, after Fragment 102, about the processes of the transformation of soul as related to the teaching of the elements. A standard text emphasizing the elemental changes include F 39 (D31b): “Sea is poured forth (from earth), and is measured in the same proportion as existed before it became earth.” The same processes continue, as elements are transmigrated into others still, as he emphasizes in F 41, with fire becoming air, which for its part becomes water.
A further line of interpretation has emphasized this as a statement on the unity of opposites. If we imagine a path literally up and down a mountain, regardless of whether one is walking up or down, the path remains the same. So, the argument goes, the path unifies the opposites of “up” and “down.” But this seems to commit a false equivocation. On this path, up remains up. Down remains down. It’s only that the path goes up and down, not that “up” becomes “down.”