Institutio Oratoria

Quintilian

Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.

But while the major premise and the reason

v4-6 p.363
may both be true and the conclusion false, yet if both are false, the conclusion can never be true.