What is "ignoratio elenchi"

n. the logical fallacy of supposing that an argument proving an irrelevant point has proved the point at issue

Ignoratio elenchi, also known as irrelevant conclusion, is the informal fallacy of presenting an argument that may or may not be logically valid, but fails nonetheless to address the issue in question. More colloquially, it is also known as missing the point.

Ignoratio elenchi falls into the broad class of relevance fallacies. It is one of the fallacies identified by Aristotle in his Organon. In a broader sense he asserted that all fallacies are a form of ignoratio elenchi.

The phrase ignoratio elenchi is . Here elenchi is the genitive singular of the Latin noun elenchus, which is . The translation in English of the Latin expression has varied somewhat. Hamblin proposed "misconception of refutation" or "ignorance of refutation" as a literal translation, John Arthur Oesterle preferred "ignoring the issue", Irving Copi, Christopher Tindale and others used "irrelevant conclusion".

● Example 1: A and B are debating as to whether criticizing indirectly has any merit in general.

A: There is no point in people ranting on social media about politics, the president is not going to read it anyway. B: But it's their social media, people can agree on making a petition or convey notice from many others that they'll be signing one based on their concerns. A: Well, I don't keep up with it anyway.

A attempts to support their position with an argument that politics ought not to be criticized because the message is not directly being heard by the head of state; this would make them guilty of ignoratio elenchi, as people such as B may be criticizing politics because they have a strong message for their peers, or because they wish to bring attention to political matters, rather than ever intending that their views would be read by the president.

● Example 2: A and B are debating about the law.

A: Does the law allow me to do that?

B: The law should allow you to do that because this and that.

B missed the point. The question was not if the law should allow, but if it does or not.

Dr Johnson's unique "refutation" of Bishop Berkeley's immaterialism, his claim that matter did not actually exist but only seemed to exist, has been described as ignoratio elenchi: during a conversation with Boswell, Johnson powerfully kicked a nearby stone and proclaimed of Berkeley's theory, "I refute it thus!" (See also argumentum ad lapidem.)

A related concept is that of the red herring, which is a deliberate attempt to divert a process of enquiry by changing the subject. Ignoratio elenchi is sometimes confused with straw man argument.