Anyway, there are no experiments in history, therefore any "theory" is untestable. History is... I'm missing a word here, but historians are scholars, not scientists.
Note that the best evidence for many things comes from naturally occurring cases that look like experiments. The link between smoking and lung cancer is most definitively shown by twin studies, for example, which are purely observational.
Anyway, there are no experiments in history, therefore any "theory" is untestable. History is... I'm missing a word here, but historians are scholars, not scientists.