Logic Me This: Moving the Goalposts
‘Logic Me This’ is a regular series on Teen Skepchick where we examine various logical fallacies in an attempt to help you think more like a Skeptic.
This week, Teen Skepchick are examining the fallacy of ‘moving the goalposts’- a fallacy commonly used by peddlers of pseudoscience to gain the advantage when arguing.
Somewhat unsurprisingly, the term for the fallacy is derived from any sport featuring goalposts. It applies to the idea that those who are debating continually “move the goalposts” away from the original demands they put upon their opponents. The phrase first came into wide use in the 1980s, drawing upon the ‘football culture’ of 80s Britain.
The basic idea of the fallacy is that two sides- let’s call them Side A and Side B- are arguing. Side A demands that Side B provide certain evidence for their claims. If Side B then go on to provide this evidence, Side A deny that this proves the claim, and instead demand more evidence. Sometimes, Side A may even ask Side B to fulfill impossible criteria, which leaves them helpless as it allows the first side to dismiss any claims of the opposite due to an apparent ‘lack of evidence’. This ties in to the ‘goalposts’ idea, as it refers to an attempt at ‘goal’- where, even if you score, the other team can simply move the posts and say you missed.
This fallacy is a favourite of creationists when debating evolutionists. Take the evolutionary link between dinosaurs and birds, which creationists deny exists. They used to demand fossil evidence to prove the theory that birds evolved from dinosaurs. Then science discovered archaeopteryx, a super-cool transitional fossil, somewhere between dinosaurs and birds. Evolutionists showed it to creationists, but of course the creationists didn’t back down. Instead they said “But they have modern feathers, designed for flight! Where’s the transition there?” But then more primitive bird fossils were found, that didn’t feature modern feathers; instead, transitional ones. Again, the creationists just insisted that there was another gap, and another, until it’s almost impossible to fill every one.
If you want to do some more reading on the fallacy of ‘moving the goalposts’, here are a few useful websites: