Creationist logical reasoning

PZ Myers discusses a Creationist with some major misconceptions about evolution:

Every time I talk to creationists, I'm always stunned at the depth of their misconceptions. There are always the same old boring arguments that are ably dismissed with a paragraph from the Index to Creationist Claims, but there are also occasions when they get, errm, creative, and unfortunately they always take your gape-mouthed I-can't-believe-you-are-so-stupid-that-you-said-that reaction as a triumphant vindication that they must be right.

Orac takes a right-wing idiot to task, and I don't need to jump in—he's done a fine job dismantling him—but I made the mistake of actually reading the ghastly blog article he's criticizing, and even worse, reading some of the comments there. The very first comment will make your jaw drop at the combination of sublime arrogance and impenetrable stupidity. There's a list of 7 objections to evolution, all wrong, but I'll spare you and show just the first.

If any two species chosen at random share a common ancestor, would that not imply that every living creature today was ultimately derived from one singular "Mother-Beast"? Just what did this creature look like (I imagine a bulbous sphere, fourteen stories in diameter, with various heads sticking out all over: cow, porcupine, squid, human, etc. Most are confused; none are happy.)

This person learned everything they needed to know about evolution from playing with Mr Potato Head at the age of 4, and has not progressed since. They have not bothered to read word one of any actual science text, but are still convinced that they can accurately summarize evolutionary theory.

It seems a particular habit -- no, compulsion -- of Creationists that the less they understand about evolution, they more they insist that they have discovered the bullet-proof flaw in it which will bring the whole ediface crashing down. The Certainty of Ignorance.

Reading the average Creationist is an experience rather like going to a car mechanic to get squealing brakes looked at. He nods sagely, then pops open the boot (the trunk for you Americans reading this), pours a bottle of oil all over your spare tyre, and exclaims "there you go, that oughta fix it". Mother-Beast indeed.

But in fairness, I can understand where the Mother-Beast concept came from. It isn't just a bizarre fantasy, invented from whole cloth. It actually makes logical sense, given the assumptions Creationists tend to share.

I don't quite understand why, but some years ago Creationists came up with the assumption that "information can never be created, only destroyed". For reasons that escape me, this meme has become exceedingly popular amongst the ignorant. It is obviously false -- by any reasonable definition of information, information gets created and destroyed all the time, and not just by intelligent agents either. There's more information in an oak tree than in the acorn it grew from.

But given this bizarro assumption of "conservation of information", then logically the earliest ancestor must have had contained all the "information" from every creature that ever lived.

See? Perfectly logical, apart from the inconvenient fact that the first assumption is a total load of bollocks. The laws of logical reasoning, like computers, suffer from Garbage In, Garbage Out:

All men are tubs of strawberry yoghurt.
George Bush is a man.
Therefore George Bush is a tub of strawberry yoghurt.

If your assumptions are garbage ("the brakes are in the spare tyre, and information can never be created"), your conclusions are garbage.

This illustrates why I get impatient with people who dismiss Creationists as merely "stupid" and "brainless" -- it isn't just lack of brain power, it is often a particular sort of highly logical, deeply intellectual stupidity. It often includes a big chunk of self-deception: consciously or unconsciously, they choose their assumptions to give the conclusion they want, no matter whether that conclusion is true or even plausible, and refuse to question those assumptions, even in the face of evidence that George Bush is not a tub of strawberry yoghurt, for fear that they will have to abandon those conclusions.

In other words, Creationism isn't about logic, or intelligence, or science. It's about emotion, mostly fear and self-perception. Find a way to break through the emotional barriers, and eventually, the anti-evolution meme will die. Look at how all but the tiniest nutcase fringe of Creationists have abandoned the Biblical ideas that the Earth is flat with four corners, held up by pillars, and that the sun moves around the Earth.