SOURCE: G. S. Kirk, "Natural Change in Heraclitus," in The Pre-Socratics: A Collection of Critical Essays, edited by Alexander P. D. Mourelatos, Anchor Books, 1974, pp. 189-96.

In the following excerpt from an essay originally published in 1951, Kirk examines Heraclitus's doctrine of change, contending that it emphasizes the order and regularity of change and not, as has been claimed, a universal and constant change.

The thought of Heraclitus of Ephesus is still often summarized as "All things are flowing," panta rhei; by which it is inferred that everything is in constant change. This summary goes back ultimately to Plato, who at Cratylus 402a wrote as follows: "Heraclitus says somewhere that everything is moving and nothing stays still, and likening things to the flow of a river he says that you could not step twice into the same river." Plato's interpretation was adopted by Aristotle, and through him by Theophrastus...