Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
further shows that definition is assisted by division, which he distinguishes from partition, making the latter the dissection of a whole into its parts and the former the division of a genus into its forms or species. The number of parts he regards as being uncertain, as for instance the elements of which a state consists; the forms or species are, however, certain, as for instance the number of forms of government, which we are told are three, democracy, oligarchy, and monarchy. It is true that he does not use these illustrations,
since, as he was writing to Trebatius, [*]( A famous lawyer, cp. III. xi. 18. v. 17. ) he preferred to draw his examples from law. I have chosen my illustrations as being more obvious. Properties have relation to questions of fact as well; for instance, it is the property of a good man to act rightly, of an angry man to be violent in speech or action, and consequently we believe that such acts are committed by persons of the appropriate character, or
In a similar way division is valuable both for proof and refutation. For proof, it is sometimes enough to establish one thing.
To be a citizen, a man must either have been born or made such.For refutation, both points must be disproved:
he was neither born nor made a citizen.