The "Not All Scotsman" Fallacy
Yet another tool in the dishonest interlocutor's belt
The "Not All Scotsman" fallacy: Dismissing a generalization of one or more members of a group by drawing attention to exceptions within that group.
People who commit logical fallacies seem to enjoy combining them in interesting ways, as though the goal is to create a line of reasoning so sophisticated in its twists and turns that few would bother trying to unpack it.
“Not All Scotsman” is the name I’ve chosen to represent one such combination, due to its resemblance to the “No True Scotsman” fallacy, although the two do not overlap.
Example
Alice: “Nonsmokers have a longer life expectancy than smokers.”
Bob: “Actually, my grandmother smoked her whole life and lived to be 102.”
This fallacy contains elements of:
Strawman - Alice wasn’t arguing that every smoker will die earlier than statistics would suggest, but Bob pretends as though that is the claim because it is easier to refute.
Red Herring - The fact that Bob’s grandmother lived to such an old age, despite being a smoker, is anecdotal and irrelevant to the larger discussion.
Special Pleading - Bob is not concerned because not all smokers live shorter-than-average lives, thus moving the goalpost.
Due to the frequency at which I encounter this type of reasoning in the wild, I suggest conveniently referring to it as the “Not All Scotsman” fallacy.