ABSTRACT
Although Heraclitus agreed with Parmenides that ‘what is’ is one, and agreed with him in attacking the idea that knowledge of many things might give understanding, and agreed with him that understanding came through harkening to logos and not through the eyes and ears alone, and that the harkening to logos was not the same as a knowledge of many things – still the differences between him and Parmenides are in many ways more striking.1 What is perhaps especially striking is that, in spite of this measure of agreement on what seem to be fundamental issues, Heraclitus does not agree that ‘what is’ must exclude ‘what is not’; although I dare say he would agree that the Pythagorean notion of to kenon (the void) was to be ruled out. Parmenides denied any motion, any kind of transformation, whereas Heraclitus said all was motion.
