Residues
The method of residues is frequently employed when the speaker is supporting a policy to be carried out, a measure to be adopted, a change to be instituted, or a law to be passed. Granting the assumption that something must be done he considers all the various methods which may be employed, disposes of them one by one as illegal, or unsuited, or clumsy, or inexpedient, leaving only one, the one he wants adopted, as the one which must be followed.
This is a good practical method of proof, provided the speaker really considers all the possible ways of proceeding and does show the undesirability of all except the one remaining.
A speaker pleading for the installation of a commission form of city control might list all the possible ways of city government, a business manager, a mayor, a commission. By disposing completely of the first two, he would have proven the need for the last. A good speaker will aways go farther than merely to reach this kind of conclusion. He will, in addition to disproving the unworthy choices, strongly support his residue, the measure he wants adopted. In supporting amounts of taxes, assessments, etc., this method may be used.
"is frequently employed when the speaker is supporting a policy to be carried out, a measure to be adopted, a change to be instituted, or a law to be passed."
One amount can be proven so large as to cause unrest, another so small as to be insufficient, a third to produce a total just large enough to meet all anticipated expenses with no surplus for emergencies; therefore the correct amount must be just larger than this but not reaching an amount likely to produce the result caused by the first considered. Used in trials of criminal cases it eliminates motives until a single inevitable remainder cannot be argued away.
This may be the clue to follow, or it may be the last one of all suspected persons. Burke considered several possible ways of dealing with the American colonies; one he dismissed as no more than a "sally of anger," a second could not be operated because of the distance, a scheme of Lord North's he proved would complicate rather than settle matters, to change the spirit of America was impossible, to prosecute it as criminal was inexpedient, therefore but one way remained, to conciliate the spirit of discontent by letting the colonies vote their own taxes. It is interesting that what Burke described as the sally of anger was the way the matter was actually settled—Great Britain had to give up the American colonies.
This method is also called elimination.