Quintilian: Use

“For it is feeling and force of imagination that makes us eloquent.”
Pectus est enim quod disertos facit, et vis mentis.

Quintilian

Book X, Chapter VII, 15
De Institutione Oratoria (c. 95 AD)

Feeling , Imagination

“We should not speak so that it is possible for the audience to understand us, but so that it is impossible for them to misunderstand us.”
Quare non ut intellegere possit sed ne omnino possit non intellegere curandum.

Quintilian

Book VIII, Chapter II, 24
De Institutione Oratoria (c. 95 AD)

Understanding

“Accordingly, the first essential is that those feelings should prevail with us that we wish to prevail with the judge, and that we should be moved ourselves before we attempt to move others.”
Primum est igitur ut apud nos valeant ea quae valere apud iudicem volumus, adficiamurque antequam adficere conemur.

Quintilian

Book VI, Chapter II, 28; translation by H. E. Butler
De Institutione Oratoria (c. 95 AD)

Feeling

“It is a complaint without foundation that "to very few people is granted the faculty of comprehending what is imparted to them, and that most, through dullness of understanding, lose their labor and their time." On the contrary, you will find the greater number of men both ready in conceiving and quick in learning, since such quickness is natural to man. As birds are born to fly, horses to run, and wild beasts to show fierceness, so to us peculiarly belong activity and sagacity of understanding.”
Falsa enim est querela, paucissimis hominibus vim percipiendi quae tradantur esse concessam, plerosque vero laborem ac tempora tarditate ingenii perdere. Nam contra plures reperias et faciles in excogitando et ad discendum promptos. Quippe id est homini naturale, ac sicut aves ad volatum, equi ad cursum, ad saevitiam ferae gignuntur, ita nobis propria est mentis agitatio atque sollertia.

Quintilian

Book I, Chapter I, 1; translation by Rev. John Selby Watson
De Institutione Oratoria (c. 95 AD)

Men , People , Understanding , Nature

“Nature herself, indeed, seems to have given music to us as a benefit, to enable us to endure labors with greater facility, for musical sounds cheer even the rower; and it is not only in those works in which the efforts of many, while some pleasing voice leads them, conspire together that music is of avail, but the toil even of people at work by themselves finds itself soothed by song, however rude.”

Quintilian

H. E. Butler's translation:
Indeed nature itself seems to have given music as a boon to men to lighten the strain of labour: even the rower in the galleys is cheered to effort by song. Nor is this function of music confined to cases where the efforts of a number are given union by the sound of some sweet voice that sets the tune, but even solitary workers find solace at their toil in artless song.
Book I, Chapter X, 16
De Institutione Oratoria (c. 95 AD)
Original: (la) Atque eam natura ipsa videtur ad tolerandos facilius labores velut muneri nobis dedisse, si quidem et remigem cantus hortatur; nec solum in iis operibus in quibus plurium conatus praeeunte aliqua iucunda voce conspirat, sed etiam singulorum fatigatio quamlibet se rudi modulatione solatur.

People , Nature , Music , Effort