When was Chopin born, when did he die, where did Chopin end and his brother begin ?
All concrete questions we can definitively answer.
That's the terrible thing about individuals, the thing that made modernists from all camps hate them so : if forces one to take the coke out of one's nose and actually deal with hard facts and numbers and dates.
But imagined communities - those hallucinations shared by tenured professors and certified lunatics in the 1930s , now that was their preferred cup of tea.