no true Scotsman fallacy English

Meaning no true Scotsman fallacy meaning

What does no true Scotsman fallacy mean?

no true Scotsman fallacy noun

— The logical fallacy of attempting to retain an unreasoned assertion by excluding the case given in a counterexample, as in: "No Scotsman puts sugar on his porridge." "I am Scottish, and I put sugar on my porridge." "Well, no true Scotsman puts sugar on his porridge."