No True Scotsman
Defending a generalization by redefining it on the fly to exclude any counterexample.
- informal
The no true Scotsman fallacy shields a sweeping claim from counterexamples by arbitrarily revising it after the fact: when an exception appears, the term is redefined (“no true X would do that”) so the case no longer counts. The claim is made unfalsifiable instead of being defended with evidence.
Examples
- “No real fan would skip the playoff game.” “But Sam's a huge fan and he skipped it.” “Then he was never a real fan.”
- “Programmers always document their code.” “My friend's a programmer and never does.” “A genuine programmer always would.”
Why it works & how to counter
Persuasive because the redefinition sounds like a principled standard. Counter it by pointing out that the rule is being reshaped to dodge the counterexample, which makes it impossible to disprove.