No true Scotsman
[1][2][3] Rather than admitting error or providing evidence to disprove the counterexample, the original claim is changed by using a non-substantive modifier such as "true", "pure", "genuine", "authentic", "real", or other similar terms.[4][2] Philosophy professor Bradley Dowden explains the fallacy as an "ad hoc rescue" of a refuted generalization attempt.The "no true Scotsman" fallacy is committed when the arguer satisfies the following conditions:[3][4][6] An appeal to purity is commonly associated with protecting a preferred group.[4] The description of the fallacy in this form is attributed to British philosopher Antony Flew, who wrote, in his 1966 book God & Philosophy, In this ungracious move a brash generalization, such as No Scotsmen put sugar on their porridge, when faced with falsifying facts, is transformed while you wait into an impotent tautology: if ostensible Scotsmen put sugar on their porridge, then this is by itself sufficient to prove them not true Scotsmen.In his 1975 book Thinking About Thinking, Flew wrote:[4] Imagine some Scottish chauvinist settled down one Sunday morning with his customary copy of The News of the World.Yet the very next Sunday he finds in that same favourite source a report of the even more scandalous on-goings of Mr Angus McSporran in Aberdeen.