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 good delivery is undoubtedly impossible for one who cannot remember what he has written, or lacks the quick facility of speech required by sudden emergencies, or is hampered by incurable impediments of speech. Again, physical uncouthness may be such that no art can remedy it,
while a weak voice is incompatible with first-rate excellence in delivery. For we may employ a good, strong voice as we will; whereas one that is ugly or feeble not only prevents us from producing a number of effects, such as a crescendo or a sudden fortissimo, but at times forces faults upon us, making us drop the voice, alter its pitch and refresh the hoarseness of the throat and fatigue of the lungs by a hideous chanting intonation. However, let me now turn to consider the speaker on whom my precepts will not be wasted.
All delivery, as I have already said, is concerned with two different things, namely, voice and gesture,