The everlasting and exclusive coming-to-be, the impermanence of everything actual, which constantly acts and comes-to-be but never is, as Heraclitus teaches it, is a terrible, paralyzing thought. Its impact on men can most nearly be likened to the sensation during an earthquake when one loses one's familiar confidence in a firmly grounded earth. It takes astonishing strength to transform this reaction into its opposite, into sublimity and the feeling of blessed astonishment.”
Friedrich Nietzsche, Philosophy in the Tragic Age of the Greeks, Regnery Publishing, 1998, 117. (p.58)