Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
In all cases, however, in which we enquire into the nature and meaning of an act, and which can be considered by themselves apart from all considerations of persons and all else that gives rise to the actual cause, there are clearly three points to which we must give attention, namely Whether it is, What it is and Of what kind it is. But as there are certain
places[*](See above § 20.) of argument which are common to all three questions, this triple division is impracticable and we must therefore consider these questions rather in connexion with those
placesin which they most naturally arise.
Arguments, then, may be drawn from definition, sometimes called finitio and sometimes finis. Definition is of two kinds. We may ask whether a particular quality is a virtue or make a definition precede and ask what is the nature of a virtue. Such a definition is either stated in general terms, such as Rhetoric is the science of speaking well, or in detail, such as Rhetoric is the science of correct conception, arrangement and utterance, coupled with a retentive memory and a dignified delivery.
we may define a word by giving its content as in the preceding instances, or by etymology: we may for instance explain assiduus [*]( Paulus (exc. Fest.) gives the following explanation of this absurd derivation, for which Cicero tells that Aelius Stilo was responsible: Some think that assiduus was originally the epithet applied to one who served in the army at his own expense, contributing an as ( i.e. instead of receiving it)! ) by deriving it from as and do, locuples [*](locheples ( wealthy ) is derived from locus = the posses sors of many places. ) by deriving it from copia locorum, pecuniosus [*](pecuniosus ( moneyed ) is derived from pecus = rich in herds. ) from copiapecorum. Genus, species, difference and property seem more especially to afford scope for definition, for we derive arguments from all of these.
Genus is of little use when we desire to prove a species, but of great value for its elimination. A tree is not necessarily a plane tree, but that which is not a tree is certainly not a plane tree; again, a virtue is not necessarily the virtue of justice, but that which is not a virtue is certainly not justice. We must proceed from the genus to the ultimate species; [*](cp. § 5. ) for example, to say that man is an animal will not suffice; for animal merely gives us the genus: nor yet will the addition of the words
subject to deathbe adequate; for although this epithet gives us a species, it is common to other animals as well. If, however, we define man as a rational animal, we need nothing further to make our meaning clear.