Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
It will be necessary
Now I should regret that anyone should censure my conduct in suggesting that a statement which is wholly in our favour should be plausible, when as a matter of fact it is true. There are many things which are true, but scarcely credible, just as there are many things which are plausible though false. It will therefore require just as much exertion on our part to make the judge believe what we say when it is true as it will when it is fictitious.
These good qualities, which I have mentioned above, do not indeed cease to be virtues in other portions of the speech; for it is our duty to avoid obscurity in every part of our pleading, to preserve due proportion throughout and to say nothing save what is likely to win belief. But they require special observance in that portion of the speech which is the first from which the judge can learn the nature of the case: if at this stage of the proceedings he fails to understand, remember or believe what we say, our labour is but lost in the remainder of the speech.