Ad hominem

An ad hominem argument, or argumentum ad hominem (Latin, literally "argument against the man [or person]"), is a fallacy that involves replying to an argument or assertion by attempting to discredit the person offering the argument or assertion. Ad hominem rebuttals are one of the best-known of propagandist tactics.

Simply, it is a refutation of a proposition, based solely upon some unrelated fact about the person presenting the proposition. Such refutation is said to be "against the person" (ad hominem) and not their proposition. Properly, it consists of saying that an argument is wrong because of something about the individual or organization is in error rather than about the argument itself. Moreover, it is not necessary to insult the individual or organization whose argument is attacked in order to commit the ad hominem  attack. Rather, it must be clear that the purpose of the characterization is to discredit the person offering the argument, and, specifically, to invite others to discount his arguments.

Three traditionally identified varieties include:


 * Ad hominem abusive
 * Involves merely (and often unfairly) insulting the opponent.
 * Involve pointing out factual but damning character flaws or actions.
 * Insults and damaging facts simply do not undermine what logical support there might be for one's opponent's arguments or assertions.


 * Ad hominem circumstantial
 * Involves pointing out that someone is in circumstances such that he or she is disposed to take a particular position.
 * Constitutes an attack on the bias of a person.
 * Does not make one's opponent's arguments, from a logical point of view, any less credible to point out that one's opponent is disposed to argue that way.


 * Ad hominem tu quoque (literally, "at the person, you too")
 * Also called the "hypocrisy" argument.
 * Occurs when a claim is dismissed either because it is inconsistent with other claims which the claimant is making or because it is inconsistent with the claimant's actions.

As technique of propaganda, despite its usual lack of subtlety, it is powerful and frequently used (and, sometimes, excessively). Anyone involved in political discourse, and public discourse in general, would do well to become acquainted with it.

See also: fundamental attribution error

Portions of this article were adapted from Wikipedia's Ad hominem article.