Ad Hominem: Attacking the Person, Not the Argument

Recognize when a response targets the arguer's character instead of the reasoning.

An ad hominem fallacy, Latin for 'to the person,' rejects an argument by attacking the person making it rather than the argument itself. Whether a speaker is unlikable, young, inexperienced, or inconsistent does not, by itself, show that their reasoning is wrong. Worked example: a student council member proposes extending library hours, citing survey results showing that 60 percent of students want later access. An opponent replies, 'Why should we listen to someone who is always late to meetings? ' The reply says nothing about the survey or the proposal.

Even if the member is often late, the evidence for longer hours stands or falls on its own. A related version, sometimes called tu quoque ('you too'), dismisses criticism by pointing out the critic's hypocrisy: 'You tell me to recycle, but you drive a car. ' The critic may be inconsistent, but recycling may still be wise. Note the exception: a person's character can matter when the argument depends on trusting their testimony.

• 1Ad hominem attacks the person, not the argument.
• 2Tu quoque dismisses criticism by alleging hypocrisy.
• 3Character matters only when an argument rests on trusting testimony.