VESPERS
In which Alinardo seems to give valuable information, and William reveals his method of arriving at a probable truth through a series of unquestionable errors.

Later William descended from the scriptorium in good humor. While we were waiting for suppertime, we came upon Alinardo in the cloister. Remembering his request, I had procured some chickpeas the day before in the kitchen, and I offered them to him. He thanked me, stuffing them into his toothless, drooling mouth. “You see, boy?” he said. “The other corpse also lay where the book announced it would be. ... Now wait for the fourth trumpet!”
I asked him why he thought the key to the sequence of crimes lay in the book of Revelation. He looked at me, amazed: “The book of John offers the key to everything!” And he added, with a grimace of bitterness, “I knew it, I’ve been saying as much for a long time. ... I was the one, you know, to suggest to the abbot ... the one we had then ... to collect as many commentaries on the Apocalypse as possible. I was to have become librarian. … But then the other one managed to have himself sent to Silos, where he found the finest manuscripts, and he came back with splendid booty. ... Oh, he knew where to look; he also spoke the language of the infidels. ... And so the library was given into his keeping, and not mine. But God punished him, and sent him into the realm of darkness before his time. Ha ha ...” He laughed in a nasty way, that old man who until then, lost in the serenity of his old age, had seemed to me like an innocent child.
“Who was the monk you were speaking of?” William asked.
He looked at us, stunned. “Whom was I speaking of? I cannot remember ... it was such a long time ago. But God punishes, God nullifies, God dims even memories. Many acts of pride were committed in the library. Especially after it fell into the hands of foreigners. God punishes still. ...”
We could get no more out of him, and we left him to his calm, embittered delirium. William declared himself very interested in that exchange: “Alinardo is a man to listen to; each time he speaks he says something interesting.”
“What did he say this time?”
“Adso,” William said, “solving a mystery is not the same as deducing from first principles. Nor does it amount simply to collecting a number of particular data from which to infer a general law. It means, rather, facing one or two or three particular data apparently with nothing in common, and trying to imagine whether they could represent so many in?stances of a general law you don’t yet know, and which perhaps has never been pronounced. To be sure, if you know, as the philosopher says, that man, the horse, and the mule are all without bile and are all long-lived, you can venture the principle that animals without bile live a long time. But take the case of animals with horns. Why do they have horns? Suddenly you realize that all animals with horns are without teeth in the upper jaw This would be a fine discovery, if you did not also realize that, alas, there are animals without teeth in the upper jaw who, however, do not have horns: the camel, to name one. And finally you realize that all animals without teeth in the upper jaw have four stomachs. Well, then, you can suppose that one who cannot chew well must need four stomachs to digest food better. But what about the horns? You then try to imagine a material cause for horns—say, the lack of teeth provides the animal with an excess of osseous matter that must emerge somewhere else. But is that sufficient explanation? No, because the camel has no upper teeth, has four stomachs, but does not have horns. And you must also imagine a final cause. The osseous matter emerges in horns only in animals without other means of defense. But the camel has a very tough hide and doesn’t need horns. So the law could be ...”
“But what have horns to do with anything?” I asked impatiently. “And why are you concerne............