Montaigne on eloquence and accident

'Tis said of Severus Cassius that he spoke best extempore, that he stood more obliged to fortune than to his own diligence; that it was an advantage to him to be interrupted in speaking, and that his adversaries were afraid to nettle him, lest his anger should redouble his eloquence. I know, experimentally, the disposition of nature so impatient of tedious and elaborate premeditation, that if it do not go frankly and gaily to work, it can perform nothing to purpose. We say of some compositions that they stink of oil and the lamp, by reason of a certain rough harshness that laborious handling imprints upon those where it has been employed ... I am always worst in my own possession, and when wholly at my own disposition: accident has more title to anything that comes from me than I; occasion, company, and even the very rising and falling of my own voice, extract more from my fancy than I can find, when I sound and employ it by myself. By which means the things I say are better than those I write, if either were to be preferred, where neither is worth anything. This, also, befalls me, that I do not find myself where I seek myself, and I light upon things more by chance than by any inquisition of my own judgment. (from Michel de Montaigne: "Of Quick or Slow Speech")