This man's work survives only in fragments and his most notable dictum may be a misquote of a fragment which states "Upon those who step into the same rivers, different and again different waters flow.
Plato records Socrates arguing that the ones who first named Cronos and Rhea the ancestors of the gods must have agreed with the doctrines of this thinker. That conversation is recorded in the Cratylus, while the Theatetus argues that this thinker's major idea renders knowledge through perception impossible. This thinker offered the example of the sea being "the purest and most polluted water," to illustrate his doctrine of the unity of opposites, a consequence of this philosopher's theory of the universal principle he called logos. This man's work survives only in fragments and his most notable dictum may be a misquote of a fragment which states "Upon those who step into the same rivers, different and again different waters flow." For 10 points, identify this ancient Greek thinker who held who held that the world was in a state of constant flux.
Plato records Socrates arguing that the ones who first named Cronos and Rhea the ancestors of the gods must have agreed with the doctrines of this thinker.
Heraclitus