Tu Quoque
Also known as: appeal to hypocrisy, you-too fallacy
Dismissing criticism by pointing out that the critic doesn't live up to it themselves. Their hypocrisy doesn't make the criticism false.
Examples
A doctor examines a patient during a routine visit.
Dr. Okafor: “Your test results suggest it’s time to quit smoking — it’s raising your blood pressure and straining your heart.” Mr. Diallo: “You reek of cigarettes yourself. Don’t lecture me.”
Mr. Diallo never addresses the medical evidence. He rejects the advice because the person giving it doesn’t follow it — even though the doctor’s own habits have no bearing on whether the advice is medically sound.
Online, it surfaces whenever a correction gets answered with a counter-correction:
Comment: “This proposal reuses copy-pasted code in three places — that’s going to be a maintenance headache.” Reply: “Look who’s talking. Your last pull request had five TODOs still in it.”
The reply says nothing about whether the copy-pasted code is actually a problem.
Why the reasoning fails
Tu quoque treats “you don’t practice what you preach” as if it disproves what’s being preached. But a claim’s truth doesn’t depend on the messenger’s consistency: a doctor who smokes can still be right that smoking is harmful, and a sloppy pull request can still contain a valid criticism of a different one. The fallacy conflates two separate questions — is this claim true, and does this person live up to it — and answers the first using evidence that only speaks to the second. At most, hypocrisy is a reason to question someone’s judgment in general; it’s never evidence against a specific factual claim they’ve made.
How to respond
- Separate the claim from the person: “Whether or not I do it too, is the advice itself right?”
- Acknowledge the hypocrisy without letting it settle the argument: “Fair, that’s inconsistent of me — but it doesn’t change whether the point stands.”
- Ask them to engage with the substance: “Setting me aside, what’s actually wrong with the reasoning?”
- Notice when hypocrisy really is the topic. If the conversation is specifically about someone’s integrity or trustworthiness, not a separate factual claim, pointing out inconsistency is relevant rather than a fallacy.