悪事を働こうとする者は、いつもなにかしらの口実をみつけるもの。そしてそういう相手とは、どんなに議論をしても無駄である -- イソップ童話の有名な一編。
As a Wolf was lapping at the head of a running brook, he spied a stray Lamb paddling at some distance down the stream. Having made up his mind to seize her, he bethought himself how he might justify his violence. "Villain," said he, running up to her, "how dare you muddle the water that I am drinking?" "Indeed," said the Lamb, humbly, "I do not see how I can disturb the water, since it runs from you to me, not from me to you." "Be that as it may," replied the Wolf, "it was but a year ago that you called me many ill names." "O Sir," said the Lamb, trembling, "a year ago I was not born." "Well," replied the Wolf, "if it was not you it was your father, and that is all the same; but it’s no use trying to argue me out of my supper;" and without another word he fell upon the poor, helpless Lamb and tore her to pieces.