No true Scotsman - WikipediaFor the practice of wearing a kilt without undergarments, see True Scotsman. No true Scotsman or appeal to purity is an informal fallacy in which one attempts to protect an a posteriori claim from a falsifying counterexample by covertly modifying the initial claim.[1][2][3] Rather than admitting error or providing evidence that would disqualify the falsifying counterexample, the claim is modified
