Proverbs 12:15 (KJV) says, "The way of a fool is right in his own eyes: but he that hearkeneth unto counsel is wise." During the time described in Judges 21:25, the people of Israel had no one to guide them in the law of God and experienced series of disasters and defeats. As they did according to their own beliefs not unto the law, they fell into wickedness and drew farther way from God. This was why God sent Israel the Judges, so the people could see their wrongdoings and repent, returning the nation to victory.