No true Scotsman

No true Scotsman is an informal logical fallacy, an ad hoc attempt to retain an unreasoned assertion.^[1] When faced with a counterexample to a universal claim, rather than denying the counterexample or rejecting the original universal claim, this fallacy modifies the subject of the assertion to exclude the specific case or others like it by rhetoric, without reference to any specific objective rule.

Origin

The use of the term was advanced by philosopher Antony Flew in his 1975 book Thinking About Thinking: Do I sincerely want to be right?.^[2]

Imagine Hamish McDonald, a Scotsman, sitting down with his Glasgow Morning Herald and seeing an article about how the "Brighton Sex Maniac Strikes Again." Hamish is shocked and declares that "No Scotsman would do such a thing." The next day he sits down to read his Glasgow Morning Herald again and this time finds an article about an Aberdeen man whose brutal actions make the Brighton sex maniac seem almost gentlemanly. This fact shows that Hamish was wrong in his opinion but is he going to admit this? Not likely. This time he says, "No true Scotsman would do such a thing."

—Antony Flew, Thinking About Thinking

When the statement "all A are B" is qualified like this to exclude those A which are not B, this is a form of begging the question; the conclusion is assumed by the definition of "true A".

Examples

A simple rendition would be:

Alice: All Scotsmen enjoy haggis.

Bob: My uncle is a Scotsman, and he doesn't like haggis!

Alice: Well, all true Scotsmen like haggis.

An example of a political application of the fallacy could be in asserting that "no democracy starts a war" (which is also a Straw man), then distinguishing between mature or "true" democracies, which never start wars, and "emerging democracies", which may start them.^[3] At issue is whether or not something labeled as an "emerging democracy" is actually a democracy or something in a different conceptual category.

Discussion

This unreferenced section requires citations to ensure verifiability.

The appearance of this fallacy should not be confused with actually failing to meet criteria. In the Scotsman and haggis example, it is quite doubtful that the widely accepted definition of a Scotsman necessarily includes liking haggis. (It is more likely to include being born of Scottish parents.) To Alice it does include liking haggis; to Bob and, probably, to the reader of the above section, it does not. On the other hand, consider a conversation along these lines:

Deb: All vegetarians refuse to eat steak.

Jake: My aunt is a vegetarian, and she eats steak all the time!

Deb: Well, then she's not really a vegetarian.

In this example, Deb's reply is reasonable, because it is widely accepted that being a vegetarian does necessarily involve refusing to eat meat. Indeed, there is little else usually considered fundamental to being a vegetarian. Therefore, if Jake's aunt eats steak regularly, she is probably not a vegetarian by the widely accepted definition of the word—even if she claims to be one.

Considering this, we can see that complications will arise whenever the definition of a thing is unclear. Whereas concrete nouns are (for practical purposes) usually easy to identify, many abstract nouns express something that meets a set of criteria. For example, if we describe a person as politically "left-wing", we usually mean that the person holds a particular set of political beliefs. But it might not be possible to formulate an exhaustive list of these beliefs; and if such a list did exist, should we require that a person agree to all of them to qualify as left-wing? If not, how many are required to be "truly" left-wing? What if the person takes a left-wing stance on some issues, and a right-wing stance on other issues? The problem is that while there probably is a threshold above which it is universally accepted that a person is left-wing and not right-wing, it is very difficult to determine this threshold.

The threshold may even be subject to personal opinion. We can see this in the classic "no true Scotsman" example. The association of names to concepts is not always black and white, nor does everybody who uses a certain name consider that it applies to the exact same range of concepts. It could very well be the case that Alice only uses the term "Scotsman" to refer to people who like haggis, while Bob uses it to refer to people born of Scottish parents. If that is so, Alice is in fact properly conforming to her definition, but not to Bob's, but unfortunately each of them incorrectly assumes that the other is using their own definition.

Ideally, each participant in an argument should be aware of what the others mean by the terms under discussion. Sometimes they may not agree on a definition. For example, Alice doesn't accept Bob's use of "Scotsman", probably because for her the term really does include liking haggis. Bob thinks the term came to mean that for her because she strongly associates the quality of being born of Scottish parents with other qualities that are stereotypical of that one, including liking haggis. He therefore attempts to show that the association is invalid. But Alice does not think of it as an association; she thinks of the quality as part of the definition. The two might never come to terms on whether it is part of the definition or not.

See also

• Cognitive dissonance
• Equivocation
• Euphemism
• Loaded language
• Moving the goalposts
• Persuasive definition
• Reification (fallacy)
• Epistemic commitment

References