" Look at a strung bow lying on the ground or leaning against a wall. No movement is visible. To the eyes, it appears a static object, completely at rest. But in fact, a continuous tug-of-war is going on within it, as will become evident if the string is not strong enough, or is allowed to perish. The bow will immediately take advantage, snap it and leap to straighten itself, thus showing that each had been putting forth effort all the time. The harmonia was a dynamic one of vigorous and contrary motions neutralized by equilibrium and so unapparent. "

― W.K.C. Guthrie , A History of Greek Philosophy, Volume 1: The Earlier Presocratics and the Pythagoreans