The "no true scotsman" fallacy

The usage of the so-called "no true scotsman" fallacy can be a bit hard to understand as an actual argument. (In other words, it can be hard to understand how it could be used in a serious argument.) After all, it just sounds like a comical quip, rather than anything said seriously.

The classical rendition of the fallacy is as follows:

Person A: "No Scotsman puts sugar on his porridge."

Person B: "I am Scottish, and I put sugar on my porridge."

Person A: "Well, no true Scotsman puts sugar on his porridge."

There is, however, a form of this fallacy that's surprisingly often used in Christian apologetics, most often by those who claim that Christians are different from other people thanks to the fact that the Holy Spirit is affecting them.

For example, a common claim is that Christians would never mass-murder people. Now if you bring up a counter-example ("this person was a devout Christian, and he mass-murdered people") the standard answer is the fallacy in its purest form: "He wasn't really a Christian."

This is basically a circular argument that's used to dodge any possible counter-arguments to the claim. The claim becomes basically impossible to prove wrong because any counter-example you may bring up will be countered with a simple "he/she wasn't really a Christian". It doesn't matter how deeply Christian the person might have been, it doesn't count if he was a mass-murderer.

The condition "does not commit mass-murder" (or any of the myriad other such claims) is basically implicitly added to the definition of "Christian", and thus anybody who does not fit that definition is thus "not really a Christian".

Ultimately this dodges the burden of proof for a claim such as "Christians never mass-murder people" (due to God acting upon them or such) because the definition of the term is basically circular.

Why is this a form of circular argumentation? Consider it like saying "no dog is white", and if a white dog is shown to you, just dismissing it by saying "that's not really a dog." And why isn't it a dog? Because it's white and, as established, "no dog is white", duh. The claim itself becomes the definition.

The one thing you won't see in creationist displays

Young-earth creationists just love dinosaurs, especially the big ones. Wherever you see a young-earth creationist display, you will invariably see two things: A mockup ark, and dinosaurs. Lots of big dinosaurs.

What you won't see, however, is realistic raptors. In other words, raptors with feathers. The reason for this is because the second-most popular objection that young-earth creationists have about evolutionary history is that birds evolved from dinosaurs (the most common being, of course, that humans and apes have a common ancestor.)

This is actually pretty funny and hypocritical. When paleontologists come to the conclusion that dinosaurs were reptiles, they believe it. When they conclude that theropods walked like ostriches, they believe it. When they conclude what their skin probably looked like, they believe it. But when they conclude that many theropods actually had fur-like proto-feathers, if not even outright feathers, they reject that one. And the sole reason is that accepting that particular claim would be too close to accepting that birds evolved from dinosaurs for comfort. Therefore they can accept everything except that.

"Honest creationist" really is an oxymoron.