Reply #46: No True Scotsman Fallacy.

[beam me up scottie]

No true Scotsman is a term coined by Antony Flew in his 1975 book Thinking About Thinking. It refers to an argument which takes this form:
Argument: "No Scotsman puts sugar on his porridge."
Reply: "But my uncle Angus likes sugar with his porridge."
Rebuttal: "Ah yes, but no true Scotsman puts sugar on his porridge."

This form of argument is a fallacy if the predicate ("putting sugar on porridge") is not actually contradictory for the accepted definition of the subject ("Scotsman"), or if the definition of the subject is silently adjusted after the fact to make the rebuttal work.


Using the context of culture, individuals of any particular religion, for example, may tend to employ this fallacy. The statement "no true Christian" would do some such thing is often a fallacy, since the term "Christian" is used by a wide and disparate variety of people. This broad nature of the category is such that its use has very little meaning when it comes to defining a narrow property or behaviour. If there is no one accepted definition of the subject, then the definition must be understood in context, or defined in the initial argument for the discussion at hand.