The Tu Quoque fallacy (Latin for “you too”) occurs when a person attempts to discredit an opponent’s argument by asserting that the opponent fails to act consistently with their own argument. In essence, the person responds to an accusation or criticism by saying, “You do it too,” rather than addressing the validity of the argument or the evidence at hand. This fallacy is an ad hominem attack, focusing on the individual making the argument rather than the argument itself.
Suppose Alice says, “Smoking is bad for your health; you should quit,” and Bob replies, “But you smoke too, so why should I listen to you?” In this scenario, Bob is committing the Tu Quoque fallacy.
Bob’s argument is fallacious because whether or not Alice smokes has no bearing on the validity of her statement that smoking is bad for health. Even if Alice is inconsistent in her actions, the scientific evidence supporting the health risks associated with smoking remains unchanged. Alice’s inconsistency might make her a poor role model in this context, but it doesn’t invalidate the argument she presents about the dangers of smoking.
So, the Tu Quoque fallacy sidesteps the actual issue at hand and instead targets the perceived hypocrisy or inconsistency of the person making the argument. While such information might be relevant in evaluating a person’s credibility, it doesn’t address whether their argument itself is sound or valid.