The pot calling the kettle black is an informal fallacy also called Tu quoque. Another name is appeal to hypocrisy.
It happens when a person is guilty of the very thing of which they accuse another.
| “ | "Oho!" said the pot to the kettle; "You are dirty and ugly and black! Sure no one would think you were metal, Except when you're given a crack". "Not so! not so!" kettle said to the pot; |
” |
A fable, perhaps by Aesop, has a mother crab and its young, where the mother tells the child to walk straight, and is asked in return to demonstrate how that is done.
A present-day example:
It is a fallacy because a person's actions or character do not affect the logic of the argument.