[bluGill]

That isn't relevant as they didn't have the spare resources to dedicate people to the task. If they did a few smart researchers could figure something out. Just going through all their archives would have done the job if they had people to dedicate to the search (though of course they couldn't have known that and so a track to create it from scratch would also be needed).

Depending on where you are talking about there may not have been local resources to make waterproof concrete, which back to my point: they didn't have the resources if they wanted to. Though we have plenty of buildings (most obviously Cathedrals) dating to well before the rediscovery of roman concrete to prove that isn't needed. Those Cathedrals only exist because they had a few resources and so they could build them over time. Those cathedrals also were in use for church services - usually in the first year of construction - to fuel the dream.

[KineticLensman]

> Those Cathedrals only exist because they had a few resources and so they could build them over time

They also only exist because they used architectural techniques that the Romans never developed, namely the flying buttress, which could support massive relatively thin wall without hundreds of columns and arches everywhere.

[saispas]

I don't think anybody seriously suggests that the medieval period was incapable of developing anything new or of building some stunning things – it's clearly nonsense. They had as many geniuses and craftsman as any generation and they produced some wonderful things comparable to anything we can.

I don't think it's simply a matter of lack of resources, though – some of the early kings had the manpower to do things like build an 80 mile rampart between Mercia and the Welsh states.

In thinking about what you've written, I started to look for more detail on any research into why there was such a drastic change in architecture post the collapse and you're right, it clearly is more complicated than just lost knowledge. I didn't look far, only https://en.wikipedia.org/wiki/Anglo-Saxon_architecture, but that's enough to suggest that it's now accepted that conscious cultural choice had a lot to do with it as well (if not more…). So I learnt something and will dig into it more - thanks!

But I'm not sure that specific (Anglo Saxon architecture) point really negates the proposition that for a thousand years people looked back to Rome (and later Greece) writers to legitimise their knowledge. This knowledge was sought after and preserved (and amended to fit in with religious dogma, of course). There were innovators, of course, but there's a reason that writers like Galen and Vitruvius, held so much sway for so long, isn't there?

In the political sphere, there were countless (real and figurative) battles to be seen as the heir to the Roman Empire because that was what success looked like… Yes, all these states would have torn each other to shreds anyway, because that's what states do if they're not stopped, but isn't it telling that they did explicitly so in terms of being the inheritor of Rome?

Of course it's all more complicated than that, but it does seem fairly clear that the ancient world generally was seen as something to aspire to, to get back to, in a way that's probably foreign to us now.

Unless you're Mussolini, of course…