This is the final chapter of the book.
If you are not familiar with the novel, the beginning of my excerpt probably won't mean much to you as it breaks down the murder mystery that wove itself through the story. But hang in there,  it's merely the beginning of one of the greatest argumentative showdowns between two adversaries that you are likely to ever come across, and it leads to a deeply engrossing philosophical debate that speaks very much to the challenges of our own  time and is well worth listening to even if you do not know the story line.

Here is an introduction:
The story takes place in the early 14th Century, in a Benedictine monastery in the mountains of North Eastern Italy. William de Baskerville, a Franciscan monk from Scotland and his young Austrian apprentice, Adson von Melk, who is the narrator of the story – writing it, as it were, as a confessional testimony in old age – have traveled there because the abbey is to host an important meeting between rivaling fractions of the catholic church – and members of the Inquisition – to discuss important matters that will determine the future of Europe’s religious institutions and their respective positions in the dominance hierarchy. As it happens, the abbey, which is not only exceedingly wealthy but also boasts a mystical, enormous, ancient library that is off limits to all but the designated librarian and his assistant, has been befallen by tragedy: several monks are found dead under rather strange and horrific circumstances, and the abbot asks William to investigate the case. All signs point to the secretive library and a mysterious book that somebody seems dead set on not letting anybody find or read. After a week of trials, secretive nightly explorations of the library that, it turns out, is laid out as a confounding labyrinth, and too many dramatic turns of events to mention here, William and his apprentice at long last manage to find their way into the even more secretive inner sanctum of the library, the so-called Finis Africae, a chamber hidden behind a mirror, the place where they expect to find not just the book but the clue to the murders. 

This is where my reading begins.  I am using my own translation.