Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
For a large number of clients lie, and hold forth, not as if they were instructing their advocate in the facts of the case, but as if they were pleading with a judge. Consequently we must never be too ready to believe them, but must test them in every way, try to confuse them and draw them out.