Not from an historian this time, but from Bertolt Brecht in Brecht on Theatre: The Development of an Aesthetic. I’m still thinking about this one.
Historicization (p. 140)
Historical incidents are unique, transitory incidents associated with particular periods. The conduct of the persons involved in them is not fixed or ‘universally human’; it includes elements that have been or may be overtaken by the course of history, and is subject to criticism from the immediately following period’s point of view. The conduct of those born before us is alienated from us by an incessant evolution.
and then on p. 90
In other words we must drop our habit of taking the different social structures of past periods, then stripping them of everything that makes them different; so that they all look more or less like our own, which then acquires from this process a certain air of having been there all along, in other words of permanence pure and simple. Instead we must leave them their distinguishing marks and keep their impermanence always before our eyes, so that our own period can be seen to be impermanent too.