Open cultures are most of the time the best way to organise human groups. Unless the group wants to defend itself. Or when the collapse of literate civilization threatens books, reading and writing with extinction.
As ancient Roman culture was entering its dawn and doom, literacy, one of its most prominent features, left the Western marketplace, urban schools and educated elites, all places of openness and freeflow, and entered the rigid, cloistered, but safe world of Christian abbeys and monasteries. To survive, the books became household items of monastic households. Held in common by pious scribes, scholars & readers, they found the breeding ground which the outside world, bending to the will of illiterate tribes, could not guarantee.
The splendid words of the medieval West grew in splendid isolation. Nevertheless, they grew and they survived. And thus I can write my blog today, and think about things like that.
The shuttered words of medieval cloisters ensured the continuation of a millenium-old culture of the written word. It could have easily died and disappeared. It could have easily turned the treasures of ancient libraries into a glorious though lifeless ruin. Except that ruined literacy, unlike the ruined architecture of dead civilizations, is unthinkable outside its own carcass.