Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
since the man who exhausts himself by such painful diligence will have no time for more important considerations; for he will disregard the weight of his subject matter, despise true beauty of style and, as Lucilius says, will construct a tesselated pavement of phrases nicely dovetailed together in intricate patterns. [*]( In Or. xliv. 149, the lines are actually quoted quam lepide lexeis compostae Ut tesserulae oinnes arte pavimnento atque emblemate verniculato. How neatly his phrases are put together, like a cunningly tesselated pavement with intricate inlay. ) The inevitable result will be that his passions will cool and his energy be wasted, just as our dandies destroy their horses' capacity for speed by training them to shorten their paces.
Prose-structure, of course, existed before rhythms were discovered in it, just as poetry was originally the outcome of a natural impulse and was created by the instinctive feeling of the ear for quantity and the observation of time and rhythm, while the discovery of feet came later. Consequently assiduous practice in writing will be sufficient to enable us to produce similar rhythmical effects when speaking extempore.