Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
A conjecture as to a fact is confirmed by argument from something greater in the following sentence:
If a man commit sacrilege, he will also commit theft; from something less, in a sentence such as
He who lies easily and openly will commit perjury; from something equal in a sentence such as
He who has taken a bribe to give a false verdict will take a bribe to give false witness.
Points of law may be proved in a similar manner; from something greater, as in the sentence
If it is lawful to kill an adulterer, it is lawful to scourge him; from something less,
If it is lawful to kill a man attempting theft by night, how much more lawful is it to kill one who attempts robbery with violence; from something equal,
The penalty which is just in the case of parricide is also just in the case of matricide.In all these cases we follow the syllogistic method. [*](See III. vi. 15, 43, 88.)
The following type of argument on the other hand is more serviceable in questions turning
If strength is good for the body, health is no less good.
If theft is a crime, sacrilege is a greater crime.
If abstinence is a virtue, so is self-control.
If the world is governed by providence, the state also requires a government.
If a house cannot be built without a plan, what of a whole city?
If naval stores require careful supervision, so also do arms.
I am content to treat this type of argument as a genus without going further; others however divide it into species. For we may argue from several things to one or from one thing to several; hence arguments such as
What has happened once may happen often.We may also argue from a part to a whole, from genus to species, from that which contains to that which is contained, from the difficult to the easy, from the remote to the near, and similarly from the opposites of all these to their opposites.
Now all these arguments deal with the greater or the less or else with things that are equal, and if we follow up such fine distinctions, there will be no limit to our division into species. For the comparison of things is infinite; things may be more pleasant, more serious, more necessary, more honourable, more useful. I say no more for fear of falling into that very garrulity which I deprecate.
The number of examples of these arguments which I might quote is likewise infinite, but I will only deal with a very few. As an example of argument from something greater take the following example from the pro Caecina [*](XV. 43.)
Shall we suppose that that which alarms whole armies caused no alarm to a peaceful company of lawyers?As an instance of argument from something easier, take this passage
Consider whether it would have been easy for you to secure the praetorship, when he in whose favour you withdrew failed to secure election?
The following [*]( xvi. 45. Caecina had attempted to take possession of lands left him by will, but was driven off by armed force. Cicero has just pointed out that there were precedents for regarding the mere sight of armed men in occupation of the property claimed as sufficient proof of violence. ) provides an example of argument from something more difficult:
I beg you, Tubero, to remark that I, who do not hesitate to speak of my own deed, venture to speak of that performed by Ligarius; and again,
Has not Ligarius reason for hope, when I am permitted to intercede with you for another?For an argument drawn from something less take this passage from the pro Caecinaa [*](pro Lig. iii. 8 and x. 31. Cicero's point is that he has been a much more bitter opponent of Caesar than Ligarius, and yet he has been pardoned while Ligarius has not. ) :
Really! Is the knowledge that the men were armed sufficient to prove that violence was offered, and the fact that he fell into their hands insufficient?Well, then, to give a brief summary of the whole question, arguments are drawn from persons, causes, place and time (which latter we have divided into preceding, contemporary and subsequent), from resources (under which we include instruments), from manner (that is, how a thing has been done), from definition, genus, species, difference, property, elimination, division, beginnings, increase, consummation, likes, unlikes, contradictions, consequents, efficients, effects, results, and comparison, which is subdivided into several species.
I think I should also add that arguments are drawn not merely from admitted facts, but from fictitious suppositions, which the Greeks style καθ᾽ ὑπόθεσιν and that this latter type of argument falls into all the same divisions as those which I have
When I speak of fictitious arguments I mean the proposition of something which, if true, would either solve a problem or contribute to its solution, and secondly the demonstration of the similarity of our hypothesis to the case under consideration. To make this the more readily intelligible to youths who have not yet left school, I will first of all illustrate it by examples of a kind familiar to the young.