A fallacy is a mistake in the logic of one’s thinking or communicating which leads to wrong conclusions. We as those who desire to be clear thinking and accurate about the properties of reality need to be familiar with fallacies as we are presented with them, in order to hone our ability to rightly appraise truth claims.
Definition: Tu Quoque means, in Latin, “you, too” or “you, also,” and in logic refers to an informal logical fallacy which occurs when one attempts to rebut an argument by pointing out that the one making the argument does not themselves live in a manner consistent with the conclusion of the argument. The fallacy is also related to the ad hominem fallacy.
Examples: “Dad, how can you tell me to be sexually abstinent until marriage when you slept around as a teenager?”
“Abortion is murder, and so is morally evil!” “Who are you to condemn it, you had an abortion 10 years ago.”
“Christianity cannot be true, because there are a lot of Christians who don’t practice what they preach.”
Recognizing the fallacy: If someone is rejecting and argument using the word hypocrite or the phrase “pot calling the kettle black,” you may be witnessing a tu quoque.