From Chapter III., Herakleitos of Ephesos
This necessarily brings with it a certain way of looking at the change and movement of the world.
Fire burns continuously and without interruption. It is always consuming fuel and always liberating
smoke. Everything is either mounting upwards to serve as fuel, or sinking downwards after having
nourished the flame. It follows that the whole of reality is like an ever-flowing stream, and that nothing is
ever at rest for a moment. The substance of the things we see is in constant change. Even as we look at
them, some of the stuff of which they are composed has already passed into something else, while fresh
stuff has come into them from another source. This is usually summed up, appropriately enough, in the
phrase "All things are flowing" (πάντα ῥεῖ), though this does not seem to be a quotation from Herakleitos.
Plato, however, expresses the idea quite clearly. "Nothing ever is, everything is becoming"; "All things
are in motion like streams"; "All things are passing, and nothing abides"; "Herakleitos says somewhere
that all things pass and naught abides; and, comparing things to the current of a river, he says you
cannot step twice into the same stream" (cf. fr. 41)—these are the terms in which he describes the
system. And Aristotle says the same thing, "All things are in motion," "nothing steadfastly is."59
Herakleitos held, in fact, that any given thing, however stable in appearance, was merely a section in the
stream, and that the stuff composing it was never the same in any two consecutive moments. We shall
see presently how he conceived the process to operate; meanwhile we remark that this is not the most
original feature of the system. The Milesians had held a similar view.
59. Plato, Theaet. 152 e 1; Crat. 401 d 5, 402 a 8; Arist. Top. A, 11. 104 b 22 ; De caelo,
Γ, 1. 298 b 30; Phys. Θ, 3. 253 b 2.