Ignoratio elenchi
Ignoratio elenchi (which can be roughly translated by ignoring the issue; also known as "irrelevant conclusion") is the logical fallacy of presenting an argument that may of itself be valid, but which proves a different proposition than the one it is supposed to prove.For example, the prosecutor in a criminal court might argue how bad the crime is that has been committed, but if this argument is taken as an argument to convict the suspect, it is a case of ignoratio elenchi--it does not prove what it should prove, namely that the suspect is the one who committed it.
Aristotle believed that an ignoratio elenchi is a mistake made by a questioner while attempting to refute a respondent's argument. He called it an ignorance of what makes for a refutation.
