I have trouble with many so-called 'fallacies', and the 'No True Scotsman' fallacy is no exception.
Let me quote a famous line from Game of Thrones:
Any man who must say "I am the King" is no true King.
Did Lord Tywin commit the 'No True Scotsman' fallacy here?
Or another less famous quote:
Knights are sworn to defend the weak, protect women, and fight for the right, but none of them did a thing. Only Ser Dontos had tried to help, and he was no longer a knight. No more than the Imp was, nor the Hound … the Hound hated knights … I hate them too. They are no true knights, not one of them.
Did Sansa commit the No True Scotsman fallacy?
All this seems extremely counter-intuitive to me. Both Tywin's reasoning and Sansa's reasoning seem sound to me.
It seems to me that the pattern of speech condemned by the proponents of the 'No True Scotsman' fallacy goes like this:
X is Y, but X is no true Y.
This seems fallacious, as it tries to draw some middle ground between is and is not. I can understand the mathematical reasoning that X is Y if and only if X fulfills the definition of Y; anything more just fuzzies the issue and is fallacious.
But what if we treat 'X is Y, but X is no true Y' as a shorthand for a longer, though more precise version of the same statement? 'Y is a word with two definitions: Y₁ and Y₂. Thought X fulfills Y₁, X does not fulfill Y₂. And in the context of our discussion I consider Y₂ to be more relevant than Y₁.' This is valid, as words do indeed have many definitions.
In this light both Tywin's and Sansa's statements immediately seem sound. Specifically, both Twyin and Sansa seem to be pointing at the distinction between de iure and de facto.
A person is de jure a King if he's crowned a King. However, the office of a King was established to formalize supreme authority. Therefore, if a person is de jure a King, even though he has no actual authority (because he's just a figurehead), then he's not de facto a King. We may use a verbal shorthand and say he's not a true King.
Likewise, a person is, at least in theory knighted so that he can defend the weak, protect women, and fight for what is right. If a person is de jure knighted, but does not defend the weak, protect women nor fight for what is right then we can say that he's not de facto a knight. Again, we may use a verbal shorthand and say he's not a true knight.
Is this correct? Or did I make a mistake and is No True Scotsman indeed a fallacy?