The No True Scotsman: Moving Goalposts to Win Arguments
Learn to spot when people redefine categories mid-argument to dodge counterexamples and maintain false generalizations through verbal trickery
The No True Scotsman fallacy occurs when someone protects a generalization by retroactively changing the definition of the category.
This fallacy transforms objective categories into subjective ones that conveniently exclude any counterexamples.
Claims become unfalsifiable when definitions depend on the very behavior being claimed about the group.
Testing for this fallacy requires asking what specific evidence would disprove the generalization being made.
Preventing this error means establishing clear, objective definitions before evaluating any claim about a group.
You've probably encountered this scenario: someone makes a sweeping claim about a group, you provide a counterexample, and suddenly they insist your example 'doesn't really count.' The person who does this isn't necessarily lying—they're employing one of the most slippery logical fallacies in everyday discourse.
The No True Scotsman fallacy occurs when someone protects a universal generalization from counterexamples by changing the definition of the category itself. Named after a classic example involving Scottish behavior, this fallacy reveals how we unconsciously shift definitions to preserve our beliefs rather than admitting we might be wrong.
Definition Shifting: How Categories Get Retroactively Narrowed
The fallacy begins innocently enough with a universal claim: 'All Scotsmen are brave.' When confronted with Angus MacPherson, a Scotsman who fled from danger, the claim suddenly morphs: 'Well, no true Scotsman would run away.' The goalposts have moved. The category 'Scotsman' now mysteriously excludes anyone who contradicts the original claim.
This retroactive narrowing happens constantly in everyday arguments. 'Real Americans support freedom' becomes circular when anyone who questions certain policies is deemed 'not a real American.' The definition shifts from an objective criterion (citizenship) to a subjective one that conveniently supports the arguer's position. Religious groups, political parties, and professional communities all engage in this boundary-policing behavior.
The psychological appeal is obvious: we get to maintain our generalizations without the messy work of acknowledging exceptions. Instead of saying 'most Scotsmen are brave, but some aren't,' we create an imaginary subcategory of 'true' members that perfectly fits our preconceptions. This mental gymnastics preserves our worldview at the cost of logical integrity.
When someone adds qualifiers like 'true,' 'real,' or 'genuine' after you've provided a counterexample, they're likely redefining terms to avoid admitting their original claim was too broad.
Falsifiability Test: Ensuring Claims Can Actually Be Proven Wrong
A claim that cannot possibly be proven false isn't really a claim at all—it's an article of faith dressed up as an argument. The No True Scotsman fallacy creates unfalsifiable statements by making the definition depend on the very thing being claimed. If 'true' Scotsmen are defined as brave, then the statement 'all true Scotsmen are brave' becomes a meaningless tautology.
To test whether someone is committing this fallacy, ask: 'What evidence would convince you that your generalization is wrong?' If they can't provide a clear answer, or if they keep changing what counts as evidence, they're not making a logical argument. They're protecting a belief. A genuine claim about Scotsmen would have clear, objective criteria for who counts as Scottish—birthplace, citizenship, ancestry—that don't change based on the behavior being discussed.
Scientists understand this principle well. Karl Popper's criterion of falsifiability requires that scientific theories must make predictions that could potentially be proven wrong. When we apply this standard to everyday arguments, many seemingly reasonable claims reveal themselves as circular reasoning. The person making the claim has immunized their belief against any possible counterevidence.
Before accepting any generalization, ask what specific evidence would disprove it—if the answer keeps changing or doesn't exist, you're dealing with an unfalsifiable belief, not a logical claim.
Fixed Criteria: Establishing Clear Definitions Before Evaluation
The antidote to goalpost-moving is simple but requires discipline: establish your definitions before examining the evidence. If you want to claim something about a group, first specify exactly who belongs to that group using objective, unchangeable criteria. Only then can you meaningfully evaluate whether your generalization holds.
This practice transforms sloppy thinking into rigorous analysis. Instead of 'conservatives don't care about the environment,' you might claim 'people who voted Republican in 2020 are less likely to support carbon taxes.' The second statement can be tested empirically. It has clear membership criteria (voting record) and a specific claim (support for carbon taxes) that doesn't shift when counterexamples appear.
In formal logic, we call this 'operationalizing' our terms. Every category needs operational definitions—specific, measurable criteria that determine membership. Once established, these criteria cannot change mid-argument. This constraint feels limiting at first, but it's liberating: your arguments become clearer, your thinking sharper, and your conclusions more reliable. You might discover your generalizations don't hold, but that discovery is more valuable than maintaining a comfortable illusion.
Write down your definitions before making claims about any group—if you find yourself wanting to change them when counterexamples arise, your original generalization was probably false.
The No True Scotsman fallacy reveals our deep reluctance to abandon cherished generalizations. Rather than accepting that our mental categories are imperfect, we perform logical contortions to preserve them. But this preservation comes at a cost: our arguments become circular, our thinking becomes sloppy, and our beliefs become unfalsifiable.
Next time you catch yourself or others adding qualifiers like 'true,' 'real,' or 'genuine' to deflect counterexamples, pause. Return to fixed, objective definitions. Test your claims against reality rather than adjusting reality to fit your claims. In doing so, you'll discover that honest reasoning, though sometimes uncomfortable, leads to understanding that no amount of goalpost-moving can match.
This article is for general informational purposes only and should not be considered as professional advice. Verify information independently and consult with qualified professionals before making any decisions based on this content.
