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 when a reason of unusual length intervenes, it is necessary to state the final conclusion, otherwise the major premise and the reason would suffice.
Laws are silent in the midst of arms, and do not require us to await their sanction when the circumstances are such that he who would await their sanction is certain to be the victim of an unjust penalty before ever the just penalty can be claimed.[*](pro Mil. iv. 10. ) Hence it has been asserted that the form of enthymeme which is based on denial of consequents resembles a reason. But sometimes, again, it is sufficient to state a single proposition as in the example just quoted,
The laws are silent in the midst of arms.