donno if its quite that dramatic, i.e. the monostaries keeping record and thus without them we wouldnt have the written word. you forget about the role of ireland in the dark ages, and europe isnt the only place in the work that was civilized, in fact after the fall of rome all of europe was like a backwater area to the world, europe was like the 3rd world, now one went there and no one cared. the centers of the world were china, india and the middle east.
I didn't say the ENTIRE written word, but without those monasteries (and yes, a good many of them were in Ireland), we wouldn't have such writings as The Bible, "Beowulf", "The Canterbury Tales", "Sir Gawain and the Green Knight", and other pieces of literature to that effect. That's why if you read Beowulf, you will see references to both Christianity and such pagan ideas as "wyrd", which more or less means "fate". This is because (and this is the current hypothesis, mind you) the original story was pagan, and when it was copied copied by the monks, the Christian elements were added.