Continuing from the entry below, there is another way to look at this same issue.
Of course we can never be certain what a writer had in his/her mind when s/he quoted the “Bình Ngô Đại Cáo” and wrote “bắc nam.” Even though an author did not capitalize these terms, s/he might have still thought in her/his mind that these two terms referred to what we today call “China” and “Vietnam,” respectively.
However, when authors translated the “Bình Ngô Đại Cáo” into foreign languages, there was no ambiguity about what they thought. And as we saw below, there was an original French translation (1952), and an English translation (1967) that clearly saw “bắc nam” as referring to distinctions within Đại Việt, and then a second French translation (1972) that saw those same terms as referring to “the North” and “the South,” that is, to “China” and “Vietnam.”
This later French translation was produced in North Vienam, and it represents the understanding of that line that is widely believed to be accurate today.
North Vietnam in 1972 was a place where scholars believed that historical scholarship is “scientific” (khoa học). Today this term is still employed, although I find it difficult at times to understand what it really means. I’m never sure if I should translate it as “scientific” or simply “academic.”
Either way, I think that people would agree that knowledge that is “khoa học” is supposed to be produced and verified in ways that demonstrate its correctness (just as “scientific” and “academic” knowledge is).
Regardless of how that is done, I think that it is the norm in scientific/academic communities that the manner in which information gets to be accepted by scientists/academics follows a similar path.
1. There is an existing idea/view of something.
2. A scientist/academic (or a group) then challenges the existing idea/view by putting forth a new idea/view that is based on evidence.
3. The rest of the scientific/academic community then examines the argument and evidence for this new idea/view, and if they are convinced by the evidence, then they agree with and adopt this new idea/view.
In other words, for a “scientific/academic” idea/view to be accepted, an argument with supporting evidence has to be put forth, and other scientists/academics have to accept that argument based on the persuasiveness of the evidence.
In the case of the “Bình Ngô Đại Cáo,” it is clear that the current understanding of the line that refers to “bắc nam/Bắc Nam” has not always been the way it is now. In which case, there must have been a time when someone made an argument for understanding that line to be referring to “China” and “Vietnam,” and that person must have supported that argument with evidence, and that evidence must have convinced the rest of the scientific/academic community in Vietnam of its correctness.
So who made that argument, and what was the evidence that s/he provided to support the argument? I have been looking and looking for this, but I cannot find it anywhere.
If, however, it turns out that no such argument was ever made, then how do we know that the current understanding is “khoa học”?
This question is particularly important when we consider that there were intelligent and well-trained scholars in the 1950s and 1960s who did not read that line in the way that it is read today.
Who made the argument that they were wrong? Where was that argument made and published? What evidence was used to support the view that is accepted today?