Straw man

A straw man argument is an informal fallacy based on misrepresentation of an opponent's position. To "attack a straw man" is to create the illusion of having refuted a proposition by substituting it with a superficially similar yet unequivalent proposition (the "straw man"), and refuting it, without ever having actually refuted the original position.

Origin
The origins of the term are unclear; one common (folk) etymology given is that it originated with men who stood outside courthouses with a straw in their shoe in order to indicate their willingness to be a false witness, but it is unlikely that individuals would publicly declare their willingness to commit a crime outside a courthouse. Another more popular origin is a human figure made of straw, such as practice dummies used in military training. Such a dummy is supposed to represent the enemy, but it is considerably easier to attack because it neither moves, nor fights back.

In the UK, the adversary is sometimes called Aunt Sally, with reference to a traditional fairground game.

Reasoning
The straw man fallacy occurs in the following pattern of argument:


 * 1) Person A has position X.
 * 2) Person B disregards certain key points of X and instead presents the superficially similar position Y. Thus, Y is a resulting distorted version of X and can be set up in several ways, including:
 * 3) Presenting a misrepresentation of the opponent's position and then refuting it, thus giving the appearance that the opponent's actual position has been refuted.
 * 4) Quoting an opponent's words out of context — i.e. choosing quotations that misrepresent the opponent's actual intentions (see contextomy and quote mining).
 * 5) Presenting someone who defends a position poorly as the defender, then refuting that person's arguments — thus giving the appearance that every upholder of that position (and thus the position itself) has been defeated.
 * 6) Inventing a fictitious persona with actions or beliefs which are then criticized, implying that the person represents a group of whom the speaker is critical.
 * 7) Oversimplifying an opponent's argument, then attacking this oversimplified version.
 * 8) Person B attacks position Y, concluding that X is false/incorrect/flawed.

This sort of "reasoning" is fallacious, because attacking a distorted version of a position fails to constitute an attack on the actual position.

Example
Straw man arguments often arise in public debates such as a (hypothetical) prohibition debate:
 * Person A: We should liberalize the laws on beer.
 * Person B: No, any society with unrestricted access to intoxicants loses its work ethic and goes only for immediate gratification.

The proposal was to relax laws on beer. Person B has exaggerated this to a position harder to defend, i.e., "unrestricted access to intoxicants".

This is also a slippery slope fallacy.