Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
The latter, on the other hand, does imply art, but lacks the sincerity of nature: consequently in such cases the main thing is to excite the appropriate feeling in oneself, to form a mental picture of the facts, and to exhibit an emotion that cannot be distinguished from the truth. The voice, which is the intermediary between ourselves and our hearers, will then produce precisely the same emotion in the judge that we have put into it. For it is the index of the mind, and is capable of expressing all its varieties of feeling.
Therefore when we deal with a lively theme, the flow of the voice is characterised by fullness, simplicity and cheerfulness; but when it is roused to battle, it puts forth all its strength and strains every nerve. In anger