I've often thought that the best Civilization would actively maintain living examples of each historical milieu. A stone age place and a middle ages place, a mid century place, and so on. In this way the methods and knowledge of the past would not be lost, and in the event of a calamity (like a Carrington event, or nuclear war), it would accelerate our recovery. Presumably the highest tech'd civ would impose order on the rest to prevent the stronger civs attacking the weaker ones (only the strongest civ could possibly enforce this).
(The prospect of having to recapitulate the advances of the last 200 years fills me with indescribably weariness. Physical typesetting being a good example. Who is foolish enough to think you can "just read a book about it" and get a working press going?)
Interesting thought experiment. I'd wager there are equally interesting ethics challenges that would need addressing in order to actually do something like this well.
(The prospect of having to recapitulate the advances of the last 200 years fills me with indescribably weariness. Physical typesetting being a good example. Who is foolish enough to think you can "just read a book about it" and get a working press going?)