RR&R 5 - Logical Fallacies: Equivocation and No True Scotsman

Logical fallacies are mistakes in logical reasoning. We're all prone to making them, but we don't have to lie prone while others make them. Spot and correct them!

[Perfict]

The naming of the "No True Scotsman" fallacy is most often attributed to the British philosopher Antony Flew, who in his book, "Thinking About Thinking" (1975), wrote:

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


An argument has committed the "No True Scotsman" fallacy when a poorly supported premise is bolstered by a special qualified-definition, where if the definition is accepted it excludes refutation of the premise. Such as, "Mature democracies do not start wars." where in, if part of the definition of "mature democracies" is accepted as being those that do not start wars, then this statement is elevated from being a weak link as a premise in an argument, to being a simply unassailable truth.