Tu Quoque

In plain terms

Tu quoque is Latin for "you also." It answers a criticism by pointing out that the critic does, or has done, the same thing being criticized. "You can't call me out for being late, you were late last Tuesday." The critic's hypocrisy becomes the response in place of addressing the critique.

Closely related to whataboutism, but narrower. Tu quoque aims at the specific critic's personal conduct. Whataboutism aims more broadly, often at a side or group.

Why it's fallacious

The validity of a claim doesn't depend on the behavior of whoever is making it. A doctor who smokes can still truthfully advise you to quit. A politician with a spotty ethics record can still correctly point out an ethical problem in a rival. Whether the critic lives up to their own standard is a question about the critic, not about the standard.

Hypocrisy is a fair thing to notice. It can undermine someone's credibility or their moral standing to scold. It does not undermine the underlying claim.

Canonical example

A: "You shouldn't be criticizing the mayor for missing meetings. You missed six council meetings last year."

B: (was criticizing the mayor) — now, instead of continuing to make the case, has to explain absences.

The missed meetings on both sides might be true. Neither bears on whether the mayor's missed meetings are a legitimate problem. The move has successfully shifted the conversation from the mayor's performance to the critic's, which is exactly what it was supposed to do.

Counter-example (not a fallacy)

A: "We need a firm rule against council members voting on matters where they have a financial interest."

B: "Agreed. I should disclose that I hold stock in the company affected by item three, and I'll recuse myself."

This isn't tu quoque. B is accepting A's principle and applying it to themselves. That's just integrity. Tu quoque only shows up when hypocrisy is used as an evasion, not as an admission.

Also not tu quoque: pointing out that a rule is being selectively applied. "You're criticizing me for X, but the same behavior from your allies went unmentioned" is a legitimate challenge to the consistency of the rule, not a dodge of the rule itself. The test is whether the speaker is asking the rule to be applied more uniformly, or asking to be exempted from it.

How to respond when you see it

Concede the hypocrisy if it's real, then return to the claim. "Fair, I was late last Tuesday. That doesn't change whether you were late today. What's the answer on today?" Tu quoque loses its power the moment its target refuses to be shamed into silence.