The No-True-Scotsman Fallacy

Taxonomy: Logical Fallacy > Informal Fallacy > Redefinition > No-True-Scotsman Fallacy1



The origins of many logical fallacies are lost in the mists of history, but not so this one, which was first identified by philosopher Antony Flew2.


"The No-True-Scotsman Move" is the name given to this fallacy by its discoverer, Antony Flew. The name comes from a story that Flew tells:

Imagine some aggressively nationalistic Scotsman settled down one Sunday morning with his customary copy of that shock-horror tabloid The News of the World. He reads the story under the headline, "Sidcup Sex Maniac Strikes Again." Our reader is, as he confidently expected, agreeably shocked: "No Scot would do such a thing!" Yet the very next Sunday he finds in that same favorite source a report of the even more scandalous ongoings of Mr. Angus MacSporran in Aberdeen. … "No true Scotsman would do such a thing!"4

The No-True-Scotsman Move or Ploy is an unfortunate name for the fallacy since few people are likely to be familiar with Flew's story of the stereotypical Scotsman. However, the name seems to have become firmly attached to this type of move.


Most of us have been unwilling to admit we were real alcoholics. … We alcoholics are men and women who have lost the ability to control our drinking. We know that no real alcoholic ever recovers control. … Despite all we can say, many who are real alcoholics are not going to believe they are in that class. … If anyone who is showing inability to control his drinking can do the right-about-face and drink like a gentleman, our hats are off to him.5



The "no-true-Scotsman" type of redefinition usually occurs in the course of an argument or debate among two or more people. As in the case of the infamous Scotsman, an arguer makes a universal claim, such as "all swans are white" or "no swans are black". When an opponent points out that there are black swans in Australia, the arguer revises the claim to "all true swans are white" or "no real swans are black". This seems to save the arguer's claims from refutation by redefining "swan" to include whiteness and exclude blackness.6

The claim that "all swans are white" is an interesting, substantive, but false claim about the world. In contrast, the claim that "all true swans are white" is no more substantive than the claim that "all white swans are white". In other words, the no-true-Scotsman move or ploy gains truth at the cost of informativeness. The redefinition that results is true by definition, and therefore tells us only about the arguer's use of the word "swan", rather than about actual swans.


The words "true", "real", or "genuine" modifing a common noun such as "Scotsman", "swan", or "alcoholic" are warning signs. When people talk of "true patriotism", "real democracy", or "genuine liberty", an alarm should go off in your head. What's the difference between "true patriotism" and just plain patriotism? Will it turn out that those who betray their countries are "true" patriots? Will you be told that a one-party state is a "true" democracy because that party represents the interests of the people? Must you be forced to be "genuinely" free? Those who speak of "true patriotism", "real democracy", or "genuine freedom" may not be speaking of patriotism, democracy, or liberty at all, despite appearances.

Analysis of the Example:

According to the author of the "Big Book" of Alcoholics Anonymous, a "real" alcoholic can never learn to control his7 drinking. Despite the fact that the author seems to allow for the possibility that someone showing such an inability might regain it, that person would thereby not be a "real" alcoholic. Given this redefinition of the word "alcoholic", the author can truly write: "We know that no real alcoholic ever recovers control." This is because anyone who did so would not be a "real" alcoholic, even if he had shown all the other signs of alcoholism. One disadvantage of such a redefinition is that one can never be sure that someone with a drinking problem is an alcoholic until he's dead, since until then there's always a chance that he will start drinking in a controlled manner, thus proving that he never was a "real" alcoholic.


  1. Thanks to Ali Almossawi, Sasha Hettich, and Kevin Fournier for reminding me about this fallacy.
  2. Antony Flew,
    • A Dictionary of Philosophy (Revised Second Edition, 1984).
    • How to Think Straight: An Introduction to Critical Reasoning (1998), pp. 49-52, 56-58, 61.
    • An Introduction to Western Philosophy (1971), p. 393.
  3. Alan Musgrave, Common Sense, Science and Scepticism: A Historical Introduction to the Theory of Knowledge (1993), pp. 166-167.
  4. How to Think Straight, p. 49.
  5. Alcoholics Anonymous ("Big Book"), Chapter 3. This is an expanded version of an example from Julian Baggini's book The Duck That Won the Lottery (2009), chapter 99.
  6. These are both cases of high redefinition, since the class of swans is narrowed to exclude black swans. See the entry for the fallacy of Redefinition.
  7. I use the masculine pronoun in this paragraph in order to avoid the annoying and unnecessary "he or she"; of course, there are female alcoholics.