You may at one time have read or heard an explanation of the so-called “no true Scotsman fallacy” alongside an elucidation of why it is logically unsound. The only problem is, the “no true Scotsman fallacy” doesn’t exist. The confusion stems from the lack of English comprehension which has come to be a common affliction among our educated classes.
The purported fallacy runs something like this. Mr. Jones, a Welshman, and Mr. MacGregor, a Scot, are drinking tea after breakfast. Mr. Jones, reading the newspaper, tells Mr. MacGregor that a man was just convicted of raping and killing a young woman. Mr. MacGregor replies that no Scotsman would ever do such a thing. When Mr. Jones informs Mr. MacGregor that the culprit was indeed a Scotsman, Mr. MacGregor then counters by saying, “well, no true Scotsman would ever do such a thing.” To the simple-minded it looks like an open and shut case of obfuscation in which MacGregor continues to assert that a crime clearly committed by a Scotsman was in fact not committed by a Scotsman.
Students are invariably warned to beware of being deceived by this fallacy. The result is that whenever anyone avers that no true x is y [with the implication that some apparent x are y], the victims are conditioned to reject the proposition on the grounds of “the no true Scotsman fallacy.”
It is, in fact, obvious from the entire conversation that when Mr. MacGregor says “Scotsman,” he is referring to something more than the geographical fact of a person’s birth. To MacGregor, “Scottishness” is clearly a set of characteristics which include the manner in which that person behaves toward the world and toward his fellow humans. When, therefore, he says initially that no Scotsman would ever do such a thing, it is this set of characteristics to which he is referring. At that moment Jones does not grasp the point; hence his counter that the man involved is actually, to Jones’s mind, a Scotsman. MacGregor, seeing that Mr. Jones does not take his meaning, tries to elucidate by telling him that no true Scotsman--i.e., no Scot who has those traits which for MacGregor are a sine qua non of being Scottish--would do such a thing. MacGregor could possibly have chosen to express himself more clearly; but since it was academics who put the words into his mouth in the first place it is they, and not MacGregor, who must answer for his choice of words. After their last exchange, we can assume that Jones finally understands what Mr. MacGregor was trying to say since the story ends there; which is more than I can say for the thousands of professors and their ill-starred students who are left flouncing in the surf of their own shallow minds.