Why does it seem that no one knows what a No True Scotsman actually is? People are generalising it so that if you ever say that no real 'X'does 'Y', you're fallacious. This is wrong on so many levels and only proves that they don't know what a Scotsman fallacy is.
People seem to forget that this type of 'reasoning' needs to be ad hoc. Keep this in mind as I go. Secondly, in most cases of it, the meaning of a term is re-defined to exclude specific cases of something. Specific cases.Scotsman fallacies are a form of moving the goalposts.Re-defining a term to exclude people or behaviours that you don't like. Thirdly, it doesn't apply where the status of the subject is predetermined by other actions or behaviours.
When people distort this argument,they forget (Or who knows, maybe occasionally ignore) the first two parts of what constitutes a Scotsman fallacy. Thus, they may claim that any definition whatsoever that excludes any cases of something is a Scotsman fallacy. This is demonstrably false. Once something is defined as 'X', it's definition conversely serves as a definition of what is not 'X'. Whatever is the opposite of 'X', or fails to have the qualities of 'X' cannot be 'X'.
For example, if we define books as sewn or otherwise attatched together leaves of material, containing written or printed words, pictures, graphs, or other information, we likewise define what is not a book. (If it's not sewn or otherwise attatched together leaves of material, containing written or printed word, pictures, graphs, or other information, it's not a book.)
Therefore, if my friend Jeanne tells me that she has a book consisting of a single sheet of paper with a picture of Kierkegaard, she can't accuse me of ad hoc reasoning or a Scotsman fallacy when I tell her that what she has cannot be a book. The reasoning for it not being a book was not ad hoc.
People who don't know what they are doing tend to forget that it doesn't apply where the status of the subject is predetermined by other actions or behaviours.
(Which is really only a subset of the above argument.)
If what constitutes being 'Y' is determined by something or someone doing or being something, if someone or something fails to meet that predetermined condition, be it an action, behaviour, or whatever, then they aren't 'Y'
For example, it is predetermined that a natural born U.S. citizen is born either:
a) In the united states.
b) Abroad, to two U.S. Citizens.
c)Abroad, to one U.S.Citizen.
So, if we have Gertrude, who was born in France to French parents, under no accepted, pre-determined definition of 'American citizen' is she one. This is because, simply put, no naturally born American citizen is born abroad to two non-American parents.
In the same vein, it is pre-determined that a teacher has obtained a degree and has taught for some time.So if Gertrude claims to have been a teacher for 46 years, but never went to college and hasn't taught anyone, she isn't actually a teacher by the accepted definition of a teacher.
Do ya got it? It's not really that hard if you make some attempt to understand it.