No. 17 Fallacies of Ambiguity
No True Scotsman
In Turkish: Gerçek İskoç Safsatası
A counterexample showed up, so you changed the definition. The club got smaller, you stayed right.
A real fan comes to every match. Rain or mud.
Uncle Hasan’s been a fan for fifty years. His knees are gone, he watches from home.
Then he isn’t a real fan!
What is it?
When a counterexample turns up, narrowing the definition instead of backing down: “no real X does that.” The example isn’t accepted; the definition is redrawn each time to keep it out.
The pattern
- “All X do Y.”
- “Here’s an X that doesn’t do Y.”
- “Then it isn’t a real X.”
Why it fails
The claim has been made unfalsifiable: every counterexample gets expelled from the definition. An unfalsifiable claim isn’t strong, it’s empty; it says nothing. The word “real” does the work: it looks like a criterion, but the criterion is “whatever confirms what I said”.
How to spot it
- After the counterexample, the words “real”, “true”, “genuine” appear.
- The definition isn’t the same at the start and the end of the argument.
- No example that would refute the claim is ever accepted.
What to say
Pin the definition down first: “What do you mean by a real fan? What’s the test?” Then hold the example against that test. If the definition moves with the example, point at it: “A minute ago it was this, now it’s that.”
When it’s not a fallacy
Some definitions really do have edges: if “a vegetarian doesn’t eat meat”, calling a meat-eater not a vegetarian isn’t a fallacy, it’s using the word correctly. The difference is that the definition was clear and reasonable from the start, not invented when the counterexample arrived.
Examples
- Family“Nobody in our family gets divorced.” “Auntie did.” “She doesn’t really count as family.”
- Work“A good engineer wouldn’t make this mistake.” “Ahmet did.” “Then he wasn’t a good engineer.” Yesterday he was the best.
- Health“Anyone who does this diet properly loses weight.” Everyone who didn’t lose weight, by definition, didn’t do it properly.
- Football“A real fan backs the team in defeat too.” Everyone who booed after the loss becomes fake on the spot.