Logic -- "Argumentum Ad Hominem"
Without taking part in the discussion between writers on logic as to whether it is a science or an art, or a combination of both, we shall, for the present, consider it in its application to discourse as the art of correct reasoning. Every one uses logic, even though many have never looked into a textbook on logic. Perhaps no one has so mastered logic as to always reason correctly. But the more a person knows of the laws of correct reasoning, the easier it is for him to avoid fallacies in his own reasoning and to detect them in the reasoning of others. Not enough attention is given to the study of logic. In this matter our educators do greatly err. There is no excuse for compelling a student to wait till he reaches the university to acquaint himself with the laws of reasoning. No preacher should be satisfied to go through life without studying logic. It might be a good idea for religious journals occasionally to give a series of logic lessons, because reasoning is so intimately connected with studying and teaching the Bible. One should be able to reason correctly both in learning and in teaching. And a knowledge of the laws of correct reasoning will save a speaker or writer from being put to shame by a shrewd critic. To make a fallacious argument, even in support of the truth, gives an opponent an opening for attack. The pity is that in showing the fallacy of your argument he is likely to make many think he has disproved your position. Also, a fallacy in your sermon may be detected by some silent listener. If so, your sermon loses force with him.
But some arguments are classed as fallacies that are not always fallacies. Hill's Jevons puts the argumentum ad hominem down as a fallacy, but it is not always a fallacy. It may be as valid as any other argument. The ad hominem argument is an argument to the man; it is an appeal to his interests, his pride, his sense of justice and right, or his passions, etc. It depends upon the circumstances and the motive as to whether it is a fallacy. If in trying to save a man from disgraceful conduct, I appeal to his family pride and to his self-interest, I am using the argumentum ad hominem, but there is no fallacy. If your opponent is practicing some things that in principle are exactly like the thing he opposes, you may charge the inconsistency upon him with the hope of getting him to see the point and abandon his opposition. That is the argumentum ad hominem, but where is there any fallacy? If a man is opposing one thing and practicing a similar wrong, you may show him his inconsistency, and thereby induce him to abandon the wrong that he is practicing. Some one opposes the use of printed helps in teaching the Bible. You charge him with inconsistency, in that he uses songbooks and the marginal references in the Bible, which in principle are like the helps he opposes, hoping to get him to see the point and abandon his opposition. You are not appealing to his prejudice, nor his passions, nor any other unholy feeling. There is no fallacy in that sort of argument, yet it is the argumentum ad hominem. But the argumentum ad hominem is fallacious when it is an unfair appeal to personal opinions, or to one's vanity or prejudice or passions. Much of the flattery from the pulpit comes under this head. It is also a fallacy when an appeal is made to a person's hatred of sectarianism to induce him to do or not to do a certain thing.
Noah K. Davis does not class the argumentum ad hominem as a fallacy, but puts it under the heading, "Modified Forms." Concerning it he says: "The argumentum ad hominem is arguing from the premises of an opponent merely to defeat him. We accept his principles on which to base a counter argument, even if believing them false, our argument being directed against him personally, ad hominem. It aims to convict him of ignorance, bad faith, inconsistency, or illogical reasoning, and so to put him ex curia (out of court). Usually it attempts no moreCriticism is mostly in the form ad hominem, and should be distinguished from proof of the opposite or controversy."
Henry Coppee, page 147, says: "The argumentum ad hominem is not a fallacy when the design is to teach pure truth, and when no unholy passion or emotion of man is appealed to. In this application it was used by our Savior himself to the Jews on many occasions with great force and beauty. His touching and yet searching appeal to them for the woman taken in adultery sent them out one by one before his power. Each one felt the argument and admitted the conclusion." But some one may say: "To charge her accusers with the same crime did not prove her to be innocent." Certainly not; neither did the Savior intend that it should. But he intended to stop the unholy mouths of her hypocritical accusers. He knew these men cared nothing about the woman's guilt. He knew they were after him, and not her, and were using her in an effort to get him to commit himself in such a way that they could make out a case against him. The woman's guilt was a mere pretext. And the fact stands out clearly that Jesus stopped their mouths by charging that they were as guilty as she.
Again Jesus used the argumentum ad hominem. He healed a sorely afflicted woman on the Sabbath. The ruler of the synagogue became very indignant. Jesus replied: "Ye hypocrites, doth not each one of you on the sabbath loose his ox or his ass from the stall, and lead him away to watering? And ought not this woman, being a daughter of Abraham, whom Satan had bound, lo, these eighteen years, to have been loosed from this bond on the day of the sabbath?" Jesus virtually said: "If I am guilty, you are even more so, for you do a less needful thing. If you are justified in what you do, I am even more so."
Other instances could be given, but these are sufficient to show that the Savior frequently used a form of argument that is now condemned by some Christians. And yet some who condemn it use it in its fallacy form. To create the impression that all ad hominem arguments are fallacious, and then seek to create prejudice against an opponent by calling his argument an ad hominem, is an argumentum ad hominem fallacy.