There WAS no civilization in Europe proper when the Roman Empire fell. What are you talking about? In 400 AD Europe was nothing but a bunch of tribes, Franks and Goths and Celts and so on. I gather Spain had been more civilized by the Roman Empire than other parts of Europe in those early years though.
i guess being ignorent is your only defense on this, go read about the celts and norse faith, they had civilization, in fact they had better laws about women than most of the other civilizations around them!
women in celtic societies had legal rights, unlike most cultures, they could choose what they did with the property they owned and got half of the bride price.
your argument is purely ethnocencratic, just because they arn't a christian civilization doesn't mean they arn't civilized, and i find it an insulting generalization
And , the Church DID preserve the pagan classics and pass them on to Europe. This page of Schaff's History of the Church covers the period of mostly stagnation in the church of the middle ages, mentions the ABSENCE of libraries and claims that the old libraries had been destroyed by the BARBARIANS. There is no hint that Christianity had any desire to do away with libraries, but quite the reverse.
it also doens't say they didn't burn books too, but they did that later when the church had power.
you can thank the irish for preserving some of the texts as well
most of the stuff taught about the celts is just wrong, so is a lot of the stuff about the norse, like everything taught to demonize people is purely false or isolated to a small group