Ad hominem is a fallacy that attacks the person rather than the argument. You do not address the claim. You attack the claimant. You say they are stupid, biased, or hypocritical. The attack is irrelevant to the truth of the argument. Even a liar can tell the truth. Even a fool can be right.

The term is Latin for to the person. The fallacy comes in several forms. Abusive ad hominem insults the person. Circumstantial ad hominem points to the person's circumstances. Tu quoque ad hominem accuses the person of hypocrisy. All three avoid the argument. They change the subject to the person.

Ad hominem examples

• You are too young to understand economics.
• You only support that policy because you benefit from it.
• You criticize smoking, but you used to smoke.
• He is a convicted criminal, so his testimony is worthless.
• She is a woman, so she cannot be objective about this.

Ad hominem is seductive. It is easier to attack a person than an argument. It appeals to emotion. It rallies the crowd. It avoids the hard work of reasoning. But it is a fallacy. The character of the arguer is separate from the argument. A bad person can make a good argument. A good person can make a bad one. The argument stands or falls on its own merits. That is the principle. In practice, character matters in courtrooms and elections. Credibility is relevant. But credibility is not the same as truth. An ad hominem attack tries to replace truth with character. It fails. The argument remains. It must be answered.