I need to explain what I mean by "tautological and non-empirical".
Most Historicists, in my experience, attempt to identify stage of history "A" by identifying particular phenomena, such as x, y & z. When asked why x, y & z occur they claim that such phenomena are produced by stage of history A. This is what we call equivocation.
Let's say we identify:
a) stage of history A = X
b) phenomena x, y & z = Y
c) so Y signifys X
d) and X signifys Y
This is what is known as a tautology. In other words, it claims precisely noting. And so it is non-falsifiable and thus non-empirical.