Silly question

[Carol]

md: 
> That's exactly true, dialogue is ALWAYS present tense, because we don't speak in past tense unless we are narrating. Hence ALL NARATION is in past> and all DIALOGUE is in present. There are books in present tense, but not many, it's not standard, but it can be fun to read.
> 
> md
>
Carol responds:
All dialogue is *not* in the present tense. Sometimes a character has to talk about past events: "Hagrid told me that Dumbledore yelled at Snape yesterday," for example (obviously not the exact words but I shouldn't have to look them up). Or "Snape gave me detention all this week." I can find some real examples if you insist.

As for the narration being in the past tense, that's usually true, but not always. "All Quiet on the Western Front," for example, is in present tense except for the epilogue.

But we're not talking about narration here. We're talking about exposition. Bathilda Bagshot is writing "A History of Magic," which includes information about the present state of affairs (the present being the time of writing) as well as the past.

If you were writing a history of the United States, you would say that the United States *is* (not was) a country composed of fifty states.

Carol, who is not saying that "History of Magic" is written entirely in the present tense