No True Scotsman
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[edit] Definition
No True Scotsman is a type of logical fallacy in which the arguer claims that elements of class X have a property, and, when presented with a counterexample Y, asserts that Y therefore does not belong to class X.
The argument is a fallacy since it redefines the class as needed to suit the argument. In doing so, it can make any claim at all vacuously true under the new definition.
[edit] Examples
- Antagonist: "Because Christians fear God, they will act more ethically."
- Protagonist: "But Jim Bakker wasn't acting ethically when he stole millions from his church."
- Antagonist: "Yes, well, Jim Bakker seemed to be a Christian, but apparently, deep in his heart he was not."
[edit] Discussion
The rather unusual name no true Scotsman was coined by Antony Flew in his book Thinking about Thinking — or do I sincerely want to be right?, as follows:
'Imagine Hamish McDonald, a Scotsman, sitting down with his Press and Journal 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 Press and Journal 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”.'
[edit] Exceptions to the Rule
When the amendment to the definition is actually a necessary condition for membership in the class, this type of argument is not a fallacy. For example:
- Antagonist: "A vegetarian would never eat meat."
- Protagonist: "But my friend Avinder eats hamburgers all the time."
- Antagonist: "I wouldn't exactly call Avinder a vegetarian then."
This is not a fallacy since "not eating hamburgers", while not an explicit requirement of being a vegetarian, is a necessary condition. On the other hand, in the "Christian" example given above, "acting ethically" has not been established as a necessary condition of "being Christian"; in fact, this is the very matter under debate.
