Concept

Tu Quoque

Intro

Tu quoque is Latin for "you too." It is the move where you answer an argument not by dealing with the argument, but by pointing at the person making it and saying "well, you do the same thing."

Example: "You say lying is wrong, but you lied to your mom last week, so lying is fine." The catch is that whether lying is wrong has nothing to do with whether the person saying so has lied. Hypocrites can still be right. A drunk driver who tells you not to drink and drive is giving you good advice, even if he is ignoring it himself.

So the standard tu quoque move (X is a hypocrite, therefore X's claim is false) is a fallacy. It changes the subject from the argument to the arguer.

But there is one important exception. Sometimes pointing out "you too" is not about refuting the claim; it is about catching the person applying their own principle unevenly. "You charge Christians with hypocrisy when a believer falls short of Christianity, but you don't charge atheism with anything when Stalin falls short of atheist values. Apply the same standard to both." That kind of tu quoque is fair, because it is asking for a consistent standard, not flipping the score because the other side stumbled. The fallacy is in using "you too" to refute something. The legitimate version uses "you too" to expose a double standard.

The test is simple. Ask: is the you-too trying to make the claim go away, or is it trying to make the rules apply to both sides equally? The first is the fallacy. The second is plain fairness.

In full

The informal fallacy of refuting an argument by pointing to the arguer's own hypocrisy or inconsistency rather than engaging the substance of the claim. Latin tu quoque, "you too" / "you also." Canonical form: "X argues that Y is wrong. X is themselves guilty of Y (or related conduct). Therefore Y is not actually wrong (or X's argument fails)." The fallacy lies in treating the arguer's consistency as if it determined the claim's truth, when in fact the truth of "Y is wrong" is logically independent of whether X has lived up to that claim.

The fallacy is treated in modern informal-logic literature (Walton Informal Logic 2008 + dedicated articles; Hurley A Concise Introduction to Logic; Copi-Cohen-McMahon Introduction to Logic) typically as a sub-type of Ad Hominem, specifically the "tu quoque ad hominem" variant. The fallacy has distinctive features that warrant separate treatment + has a particularly important false-fallacy diagnostic: legitimate tu quoque IS possible when used as a principle-consistency-test rather than as substantive-refutation.

In apologetic discourse tu quoque is bidirectionally deployed:

Atheist deployment against Christianity: "You criticize my abortion view but your church covered up clergy abuse, so your moral authority is shot"; "You preach about love-your-enemies but Christians have killed millions in religious wars, your argument is hypocritical"; "You criticize atheist morality but Christianity has its own moral failures."
Christian counter-deployment as legitimate principle-consistency-test: "You charge me with the NTS fallacy on Crusaders but you accept the analogous 'no true atheist' move on Stalin, apply your principle consistently" (this is a legitimate tu quoque per the false-fallacy diagnostic, see No True Scotsman Charge Defeater §"Symmetric application").

The decisive distinction that runs through this entry: tu quoque as substantive-refutation = fallacy (X's hypocrisy doesn't refute the substance); tu quoque as principle-consistency-test = legitimate diagnostic (X's selective-application of a principle, exposed via "you too applied to your own case", is genuine evidence of equivocation). This distinction maps onto the same false-fallacy pattern that appears in Ad Hominem (where bias-disclosure for testimony is legitimate vs ad-hominem for refutation is fallacious) and runs through Genetic Fallacy / No True Scotsman Fallacy / Special Pleading / Begging the Question.

Canonical structure

P1: X argues for / claims Y
P2: X is themselves guilty of Y (or related conduct that contradicts Y)
C: Therefore Y is false (or X's argument fails)

The fallacy: P1 + P2 do not entail C. The truth of Y depends on Y's content + the supporting evidence + argument, not on whether X has personally adhered to Y. Bad people can give good arguments; hypocrites can articulate true principles; failed prophets can preach correct doctrine.

How to spot it (diagnostic)

The objection appeals to the arguer's hypocrisy / inconsistency rather than engaging the argument's content. The substantive case is left untouched.
The conclusion shifts from arguer-fact to claim-falsity. "X is hypocritical" is sociological / biographical fact; "Y is false" is the truth-claim; the inferential gap is the fallacy.
Counter-example test. Would the same form refute claims the speaker accepts? "You're hypocritical about your environmentalism, so climate change isn't real", same logical form; clearly fallacious. Apply the same test to the original deployment.
No engagement with the substantive argument. The objector doesn't engage which premise is false or which inference fails, only that the arguer is inconsistent.
Rhetorical-tells. "But you do X yourself" / "What about your own ___" / "Practice what you preach" / "You can't talk about Y when you do Z."

Common apologetic deployment

Atheist deployment against Christianity

"You criticize my abortion view but your church covered up clergy abuse, so your moral authority is shot." Fallacious tu quoque on abortion. The moral status of the unborn (or the philosophical premises about personhood) is logically independent of any institution's failures. The church's institutional failures + the abortion-argument's substantive case are different questions; tu quoque conflates them. (Treated in Christians Behaving Badly / No True Scotsman Fallacy.)
"Christians have killed in religious wars / persecuted heretics / supported slavery, your love-your-enemies argument is hypocritical." Fallacious tu quoque on Christian ethics. The truth of "love your enemies" (Mt 5:44 + Lk 6:27) is independent of how well any Christian has followed the teaching; the failures are condemned BY the doctrine itself (treated in Christians Behaving Badly Defeater + No True Scotsman Charge Defeater).
"You criticize atheist morality but Christianity has its own moral failures." Tu quoque shifting from substance (whether atheism can ground objective morality) to comparison (Christianity has failures too). The Moral Argument's force is on grounding of objective morality, not on predicting individual or institutional behavior.
"You don't accept the Quran/Vedas because they're old religious texts, but your Bible is also an old religious text, so you're being hypocritical." Fallacious selective tu quoque. The substantive Christian case for biblical reliability rests on specific evidence (manuscript transmission + early-eyewitness creeds + multi-attestation; see Resurrection) that is engaged on its merits independently of the question of why other texts are not similarly endorsed.
"You appeal to faith for your beliefs but expect evidence for atheist claims, that's hypocritical." Tu quoque mixed with Equivocation on "faith" (treated in Faith is Belief Without Evidence Objection). The substantive Christian engagement: pistis is trust based on evidence + relational commitment, not blind credulity; the asymmetry the tu quoque charges is real but resolves through definitional clarity.

Christian counter-deployment (legitimate principle-consistency-test cases)

The Christian apologist's symmetric counter-deployment is structurally legitimate when used as principle-consistency-test rather than substantive-refutation:

"You charge me with the NTS fallacy on 'no true Christian Crusader' but you accept 'no true atheist Stalinist', apply your principle consistently." Legitimate principle-consistency-test (treated in No True Scotsman Charge Defeater §"Symmetric application"). NOT a substantive refutation of atheism, but exposure of the asymmetric standard.
"You charge me with the genetic fallacy on 'Christianity is what your culture taught you' but exempt your own atheism from the same charge, apply consistently." Legitimate (treated in Accident of Birth Objection Defeater + Genetic Fallacy).
"You charge me with appeal-to-authority on 'Plantinga said X' but you appeal to 'Hawking said God isn't necessary' on out-of-domain questions, apply consistently." Legitimate (treated in Appeal to Authority §"Christian counter-deployment").
"You charge me with begging-the-question on 'the Bible is God's word because the Bible says so' but you assume metaphysical naturalism in your scientific arguments, apply consistently." Legitimate when carefully framed (treated in Begging the Question + God of the Gaps P1).
"You demand extraordinary evidence for theistic claims but accept ordinary evidence for naturalistic alternatives, apply your evidential standard consistently." Legitimate evidential-standard-symmetry challenge.

The legitimate counter-deployment does not refute atheism on hypocrisy grounds (that would be reciprocal tu quoque fallacy); it exposes the selective application of a principle the atheist invoked first, putting the substantive question back onto the table.

How to rebut it

1. Argument-truth is independent of arguer-consistency

The proper response to fallacious tu quoque: "My consistency or inconsistency with the principle is biographical fact; the truth of the principle is a separate question. Engage the principle on its merits." The classic articulation: bad people can give good arguments; hypocrites can articulate true principles; the moral failure of an arguer doesn't change whether their conclusions follow from their premises.

C. S. Lewis's articulation in Mere Christianity (Macmillan 1952) Book III, ch. 11 ("Faith"): "If Christianity were something we were making up, of course we could make it easier. But it is not. We cannot compete, in simplicity, with people who are inventing religions. How could we? We are dealing with Fact. Of course anyone can be simple if he has no facts to bother about." Lewis distinguishes the Christian-as-system from individual-Christian-failures throughout Mere Christianity.

2. Engage the substantive case

The proper redirect: "Set aside what I've done or failed to do. State which premise of my argument you reject and why. Show the inferential gap. Engage the content." This forces the conversation back onto evidential grounds where tu quoque deflection is no longer possible.

3. Distinguish substantive-refutation tu quoque (fallacious) from principle-consistency-test tu quoque (legitimate)

The diagnostic distinction is the work. Substantive refutation tu quoque ("you do X therefore X is OK / your argument fails") is the fallacy. Principle-consistency-test tu quoque ("you charge me with X-fallacy but you do X-equivalent, apply your principle consistently") is the legitimate diagnostic. The former substitutes hypocrisy for substance; the latter exposes equivocation without substituting refutation for substance.

The Christian apologetic literature has carefully distinguished these, the symmetric counter-deployment patterns in No True Scotsman Charge Defeater / Genetic Fallacy / Appeal to Authority / Special Pleading all operate as principle-consistency-test, not substantive-refutation.

False-fallacy examples

Cases where what looks like tu quoque is NOT actually fallacious, the "you too" move is operating as legitimate principle-consistency-test rather than as substantive-refutation.

Principle-consistency test exposing selective application. "You charge me with NTS on 'no true Christian Crusader', apply your principle consistently to 'no true atheist Stalinist'." The move is NOT refuting atheism on hypocrisy grounds; it's exposing that the atheist's NTS-charge is selectively applied. Why this isn't tu quoque fallacy: the conclusion is "the principle is selectively applied" (which is genuine logical critique) rather than "therefore atheism is false" (which would be reciprocal tu quoque fallacy). The move feeds back into the substantive engagement rather than substituting for it.
Authority-revocation when authority depends on character. "You're claiming to teach me about honesty but you've been documented lying, your authority on the topic is undermined." When the argument depends specifically on the arguer's authority + character (e.g., expert testimony, prophetic authority), inconsistency-of-character is relevant evidence about authority-weight (NOT about claim-truth). The argument's content remains evaluable separately. This is parallel to the bias-disclosure case in Ad Hominem.
Rapoport-Rules-style fairness check. Applying "would I accept this from my opponent" to one's own argument is methodological fairness-checking, not tu quoque fallacy. Daniel Dennett's Intuition Pumps (Norton 2013) frames this as part of legitimate dialectic.
Practical-ethics consistency challenge. "You demand stringent ethical standards from others but exempt yourself, your ethical theory needs to handle this asymmetry." This challenges the theory's coherence (does it have a principled basis for the asymmetric standard?), not the theorist's character. Legitimate philosophical move.
Internal-coherence challenge to a worldview. "Your worldview claims X but its application yields not-X in case Y, engage the apparent contradiction." Worldview-coherence challenges expose internal-inconsistency that warrants substantive theoretical-development response. Legitimate.
Character-testimony dependent claims. "Your testimony depends on your reliability + experience, your documented unreliability in similar contexts undermines the testimony." Standard courtroom + historical-testimony evaluation, not tu quoque.
Detecting performative contradiction. "You argue against logic using logical arguments, your move is self-undermining." Self-defeat critique, not tu quoque per se but related diagnostic family. Aristotle Metaphysics IV on the principle of non-contradiction defense uses this structure.
Christianity's own internal-standards critique. Christ's own teaching that the leaders should "do as they say but not as they do" (Mt 23:3, referring to the Pharisees) explicitly establishes that the teaching's truth is independent of the teacher's behavior. This NT-internal pattern is structurally parallel to the argument-truth-independent-of-arguer-consistency principle.

The diagnostic test: does the "you too" move conclude with substance-refutation ("therefore Y is false / X's argument fails") or with consistency-test ("therefore your principle is selectively applied, engage its symmetric application")? Substance-refutation = fallacy; consistency-test = legitimate.

When it's actually fallacious

Clear cases where the tu quoque charge sticks:

"Your church covered up clergy abuse, so your abortion argument fails." The church's institutional failures don't refute the abortion argument; the moral status of the unborn is logically independent.
"Christians have killed in religious wars, so your love-your-enemies teaching is hypocritical and therefore false." The truth of Mt 5:44 / Lk 6:27 is independent of Christian compliance; the failures are condemned BY the doctrine.
"You criticize atheist morality but Christianity has its own moral failures." The Moral Argument's substantive force is on grounding of objective morality, not on the comparative-failure-rates of Christians vs atheists.
"You're hypocritical about your environmentalism, therefore climate change isn't real." Counter-example: same logical form; clearly fallacious.
"You claim to oppose violence but you support just war, therefore your pacifism-related argument fails." Apparent inconsistency (which may or may not be real depending on the position's articulation) doesn't refute the substantive ethical case.
"You appeal to faith for your beliefs but demand evidence for atheist claims, that's hypocritical, so your case fails." Tu quoque + Equivocation; the substantive engagement (treated in Faith is Belief Without Evidence Objection) requires definitional clarity on "faith" (which resolves the apparent asymmetry).
"You criticize naturalism but you use scientific medicine when sick, therefore your anti-naturalism position is hypocritical." Methodological-naturalism-vs-metaphysical-naturalism distinction (treated in God of the Gaps P1) shows there's no inconsistency; even if there were, the substantive case is independent.
Christian counter-instance: "Atheists immorally promote abortion so atheism is false." Tu quoque from Christian-side; the moral status of abortion + the truth of atheism are independent questions.

Christian scholarly resources

Douglas Walton, Informal Logic 2nd ed. (Cambridge, 2008) + dedicated articles on tu quoque + "circumstantial ad hominem" + the legitimate-vs-fallacious distinction.
Patrick Hurley, A Concise Introduction to Logic (Cengage, multiple eds.). Standard textbook treatment.
Irving Copi, Carl Cohen, & Kenneth McMahon, Introduction to Logic (Routledge, 14th ed.). Alternate canonical textbook.
Norman Geisler & Ronald Brooks, Come, Let Us Reason: An Introduction to Logical Thinking (Baker, 1990). Christian-apologetic logic primer.
C. S. Lewis, Mere Christianity (Macmillan, 1952) Book III, ch. 11 ("Faith"). The Christian-as-system vs individual-Christian-failures distinction; foundational popular-apologetic engagement with hypocrisy-charges against Christianity.
G. K. Chesterton, Orthodoxy (1908) + The Everlasting Man (1925). The internal-standards-of-Christianity articulation that engages institution-vs-doctrine critiques.
Tom Holland, Dominion: How the Christian Revolution Remade the World (Basic, 2019). Engages the historical-Christianity-vs-Christian-doctrinal-content distinction substantively.
Edward Feser, The Last Superstition (St. Augustine's Press, 2008). Engages atheist deployments of various ad-hominem-family fallacies including tu quoque.
John Lennox, Gunning for God: Why the New Atheists Are Missing the Target (Lion, 2011). Engages tu quoque charges in the New-Atheist literature.
Daniel Dennett, Intuition Pumps and Other Tools for Thinking (Norton, 2013). Rapoport's Rules engagement with fairness-checking; related to legitimate-tu-quoque.