Contextual reading is a way of studying these fragmentary texts that concentrates on the structureof the arguments put forth by pre-Socratic philosophers, without ignoring the microtextual aspects (inother words, it seeks to clarify what textual needs use of the fragment responds to). This involves looking forbiases and paradigmatic elements that may be revealing when trying to reconstruct the philosophic thinkingof the author in question. In this case, I will concentrate on what Plato says about Heraclitus, particularly in Cratylus, to show how contextual reading sheds light on the creation of an interpretative tradition thatgained predominance in the case of Heraclitus; namely, the doctrine of perpetual flux. Inasmuch as that interpretationhas been called into doubt by many Heraclitian scholars, I propose, as a final step, to compare itto another interpretative tradition that reflects elements in common and allows us make universal use of thetestimonies we still have on the philosopher of Ephesus.