t turns out I missed #19, so all the numbers are out by one after that. Fixed now… (and the previous posts too!).
Tu Quoque is Latin for “you too” or “you also”. There are three flavours to this logical fallacy. The appeal to the common error in both sides of the discussion to excuse a mistake, the appeal to justify ones one errors based on a faulty perception of the others perceived mistakes and the discrediting of another’s failure to act consistently to their position.
The Pot Calling the Kettle Black
This is tantamount to a child in the playground excusing their bad behaviour with “X was doing it too!” Regardless of who else makes the error, it was still bad behaviour.
In the instance that a member of a discussion is caught using faulty logic or poor evidence, the perpetrator can either plead guilty, or may attempt to justify the error by citing the accuser of making the same or a similar error. This is a specific ad hominem attack attempting to shift the focus away from ones own mistakes to target the mistakes of another. In one flavour of this, the other may have indeed been mistaken, and in the other flavour, they are not. Either way, the fallacy is the same. Instead of addressing the noted error, the defendant diverts attention to some other error, whether real or not. The solution to this as someone who is called out on an error is to address the error. If the person receiving this logical fallacy, keep the focus on the error noted first, then address the accusation afterwards.
Dismissing the the Position
In this form of the logical fallacy, the position is ignored because of a self referential error in the arguments. This is a special case of the Fallacy Fallacy in that the fallacious argument becomes the focus instead of the position, which is dismissed. This can be best demonstrated in the following example:
Person A makes criticism C.
Person A is also guilty of C.
Therefore, C is dismissed.
Person 1: Drinking is bad for your health
Person 2: But your drinking!
In this case, the premise is that drinking is bad for ones health, which is dismissed by the second person because the arguer is currently drinking. Just because someone is guilty of participating in the activity or idea that is described does not make the activity or idea wrong. I can equally say that bashing my head against a wall is bad for your head whilst bashing my head against a wall. That doesn’t mean my head is not damaged by bashing my head against the wall.