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 two first species into which artificial proofs

v4-6 p.197

may be divided are, as I have already said, those which involve a conclusion and those which do not. The former are those which cannot be otherwise and are called τεκμήρια, by the Greeks, because they are indications from which there is no getting away. These however seem to me scarcely to come under the rules of art. For where an indication is irrefutable, there can be no dispute as to facts.

This happens whenever there can be no doubt that something is being or has been done, or when it is impossible for it to be or have been done. In such cases there can be no dispute as to the fact. This kind of proof may be considered in connexion with past, present or future time.