Moving the goalposts

From RationalWiki

Moving the goalposts is an informal logical fallacy in which previously agreed upon standards for deciding an argument are arbitrarily changed once they have been met. This is usually done by the "losing" side of an argument in a desperate bid to save face. If the goalposts are moved far enough, then the standards can eventually evolve^[1] into something that cannot be met no matter what. Usually such a tactic is spotted quickly.

[edit] Goalposts on wheels

This tactic is extremely common in debates with creationists, who will often say "show me an example of something evolving today," or "show me an example of information increasing through random processes." When either of these are shown to the creationist, they will suddenly change the standards of what they meant by "evolving" or "information" to try and avoid losing an argument they clearly lost. The definition between "micro" and "macro" evolution is often left exceptionally vague by creationists and intelligent design proponents just for this purpose.

An excellent example of the fallacy is when looking into a so-called "test" on creationist wiki ASK to see if information could be increased in a genome by making (a somewhat poor) analogy to the English langage. In this case, it was asked to increase the "information" in the phrase "trap big animal paws". When this was repeatedly demonstrated, new and relatively unreasonable rules - unknown from the participants in the first instance - began to appear. This, combined with outright denial and objection to the original answers, guaranteed a win in the eyes of the self-appointed judge.^[2]

[edit] Misuse

Users of this fallacy will, ironically, often invoke it to characterize the arguments of their opponents: a debater argues based upon an unorthodox definition of some term and, when the argument is demolished by presenting the orthodox or widely-accepted definition, complains that his/her opponent is "moving the goalpost." Surprisingly, this sort of thing can happen even when the user of the unorthodox definition has stated right out that the definition is unorthodox.

A specific example is the accusation of goalpost moving against proponents of evolution, when the latter state that the theory of evolution is not supposed to explain the origin of life. Although some features of natural selection are thought to be key in abiogenesis, the theory of evolution has never been about explaining how life began. That evolution was an explanation of diversity was made clear even in the earliest forms of the theory put forward by Darwin in the 19th century. In the case of this accusation, the goalposts have not been moved at all by "evolutionists" but by the creationists who unrealistically want a theory to explain something it's not supposed to; somewhat akin to demanding that the theory of gravitation should explain the orbits of electrons before accepting it as reality.

[edit] Footnotes

1. ↑ Pun intended
2. ↑ A Storehouse of Knowledge - A Test

Articles about logical fallacies
Formal fallacies
Ad hominem	Argument by assertion	Negative proof	Non sequitur
Informal fallacies
Ad hoc	Argumentum ad nauseam	Argumentum ex culo	Argument from ignorance	Argument from incredulity	Balance fallacy
Begging the question	Correlation does not equal causation	Equivocation	False analogy	False dilemma	Moving the goalposts
No True Scotsman	One single proof
Red herrings
Argumentum ad baculum	Argumentum ad populum	Argument from adverse consequences	Association fallacy	Bullshit	Poisoning the well
My enemy's enemy	Spotlight fallacy	Straw man	Style over substance fallacy	Texas sharpshooter fallacy
Conditional fallacies
Argument from authority	Galileo gambit	Slippery slope
Fallacious argument styles
Chewbacca Defense	Gish Gallop	Ham Hightail	JAQing off