An appeal to hypocrisy is a logical fallacy in which one attempts to discredit an opponent’s position by showing that the person making the argument has been unable to act in accordance with the position being argued for. By showing the person to be acting in a hypocritical manner, it is hoped that the audience will no longer take the argument seriously and that the argument will be dismissed. Rather than looking at the validity of the argument itself, the reputation of the person making the argument is looked at instead. Another term for this type of logical fallacy is “tu quoque,” which translates from Latin into English as “you too,” and suggests that the person is being inconsistent in what he says and in what he does.
See list of more fallacies, biases and heuristics.