"A whip for a horse, a bridle for the donkey, and a rod for a fool's back. Do not answer a fool according to his folly, lest you be like him. Answer a fool according to his folly, lest he be wise in his own eyes." Prov. 26:3-5 NKJ

You can always reason with a good man, never with a fool. To logically and morally attempt to reason with a fool is frustrating and futile. The writer says don't agree with a fool about what he says, or he will think he is right and continue in his folly. The Bible says, "The fool has said in his heart, there is no God." His mind may not agree with his heart, but in the spiritual realm the heart rules when one does not want there to be a God. Acknowledging God brings accountability and probable judgment into play, and a fool wants neither. It's a waste of time to answer the foolish talk of a fool.