“I really don’t know,” Severinus said. “Two dead men, both with blackened fingers. What do you deduce from that?”
“I deduce nothing: according to the rules of syllogism nihil sequitur geminis ex particularibus unquam, no law can be drawn from two single facts. First of all we have to know the law; for example, that a substance exists that blackens the fingers of those who touch it. . . .”
Triumphantly, I completed the syllogism: “. . . Venantius and Berengar have blackened fingers, ergo they touched this substance!”
“Good, Adso,” William said, “what a pity that not even your syllogism is valid, because aut semel aut iterum medium generaliter esto, and in this syllogism the middle term never appears as general. A sign that we haven’t chosen the major premise well. I shouldn’t have said that all those who touch a certain substance have black fingers, because there could also be people with black fingers who have not touched the substance. I should have said that all those and only all those who have black fingers have certainly touched a given substance. Venantius and Berengar, etc. With which we would have a Darii, an excellent third mode of the first syllogistic figure.”
“Then we have the answer,” I said, delighted.
“Alas, Adso, you have too much faith in syllogisms! What we have, once again, is simply the question. That is: we have ventured the hypothesis that Venantius and Berengar touched the same thing, an unquestionably reasonable hypothesis. But when we have imagined a substance that, alone among all substances, causes this result (which is still to be established), we still don’t know what it is or where they found it, or why they touched it. And, mind you, we don’t even know if it’s the substance they touched that brought them to their death. Imagine a madman who wants to kill all those who touch gold dust. Would we say it’s gold dust that kills?”
I was upset. I had always believed logic was a universal weapon, and now I realized how its validity depended on the way it was employed. Further, since I had been with my master I had become aware, and was to become even more aware in the days that followed, that logic could be especially useful when you entered it but then left it.
Severinus, who was surely not a logician, was meanwhile reflecting on the basis of his own experience. “The universe of poisons is various as the mysteries of nature are various,” he said. He pointed to a series of pots and ampoules, which we had already admired, neatly arranged on shelves along the walls, together with many volumes. “As I told you before, many of these herbs, duly compounded and administered in the proper dosage, could be used for lethal beverages and ointments. Over there, stramonium, belladonna, hemlock: they can bring on drowsiness, stimulation, or both; taken with due care they are excellent medicines, but in excess doses they bring on death.”
“But none of these substances would leave marks on the fingers?”
“None, I believe. Then there are substances that become dangerous only if ingested, whereas others act instead on the skin. And hellebore can cause vomiting in a person who grasps it to uproot it. Dittany and fraxinella, when in flower, bring on intoxication in gardeners who touch them, as if the gardeners had drunk wine. Black hellebore, merely at the touch, provokes diarrhea. Other plants cause palpitations of the heart, others of the head, still others silence the voice. But viper’s venom, applied to the skin and not allowed to enter the blood, produces only a slight irritation. . . . And once I was shown a compound that, when applied to the inside of a dog’s thighs, near the genitalia, causes the animal to die in a short time in horrible convulsions, as the limbs gradually grow rigid. . . .”
“You know many things about poisons,” William said with what sounded like admiration in his voice.
Severinus looked hard into his eyes for a few moments. “I know what a physician, an herbalist, a student of the sciences of human health must know.”
William remained thoughtful for some time. Then he asked Severinus to open the corpse’s mouth and observe the tongue. Severinus, his curiosity aroused, took a thin spatula, one of the instruments of his medical art, and obeyed. He uttered a cry of amazement: “The tongue is black!”
“So, then,” William murmured, “he grasped something with his fingers and ingested it. . . . This eliminates the poisons you mentioned before, which kill by penetrating the skin. But it doesn’t make our deductions any easier. Because now, for him and for Venantius, we must presume a voluntary act. They grasped something and put it in their mouths, knowing what they were doing. . . .”
“Something to eat? To drink?”
“Perhaps. Or perhaps—why not?—a musical instrument, like a flute . . .”
“Absurd,” Severinus said.
“Of course it’s absurd. But we mustn’t dismiss any hypothesis, no matter how farfetched. Now let’s return to the poisonous substance. If someone who knows poisons as you do had broken in here and had used some of these herbs of yours, could he have produced a lethal ointment capable of causing those marks on the fingers and the tongue? Capable of being mixed with food or drink, smeared on a spoon, on something that is put in the mouth?”
“Yes,” Severinus admitted, “but who? And besides, even if we accept this hypothesis, how would he have administered the poison to our two poor brothers?”
Frankly, I myself couldn’t imagine Venantius or Berengar letting himself be approached by someone who handed him a mysterious substance and being persuaded to eat it or drink it. But William did not seem upset by this unlikelihood. “We will think about that later,” he said, “because now I would like you to try to remember some event that perhaps you haven’t recalled before. Someone who asked you questions about your herbs, for instance; someone who has easy access to the infirmary . . .”
“Just a moment,” Severinus said. “A long time ago, years it was, on one of those shelves I kept a highly powerful substance, given to me by a brother who had traveled in distant lands. He couldn’t tell me what it was made of, herbs for sure, but not all of them familiar. To look at, it was slimy and yellowish; but I was advised not to touch it, because if it only came into contact with my lips it would kill me in a short time. The brother told me that, when ingested even in minimal doses, in the space of a half hour it caused a feeling of great weariness, then a slow paralysis of all the limbs, and finally death.
He didn’t want to carry it with him, and so he presented it to me. I kept it for a long time, because I meant to examine it somehow. Then one day there was a great storm up here. One of my assistants, a novice, had left the infirmary door open, and the hurricane wrought havoc in this room where we are now. Bottles broken, liquids spilled on the floor, herbs and powders scattered. I worked a whole day putting my things back in order, and I accepted help only in sweeping away the broken vessels and the herbs that could not be recovered.
At the end I realized that the very ampoule I mentioned to you was missing. At first I was worried, then I decided it had been broken and become confused with the other rubbish. I had the infirmary floor washed carefully, and the shelves. . . .”
“And you had seen the ampoule a few hours before the storm?”
“Yes . . . or, rather, no, now that I think about it. It was behind a row of pots, carefully hidden, and I didn’t check it every day. . . .”
“Therefore, as far as you know, it could have been stolen quite a while before the storm, without your finding out?”
“Now that I think about it, yes, unquestionably.”
“And that novice of yours could have stolen it and then could have seized the occasion of the storm deliberately to leave the door open and create confusion among your things?”
Severinus seemed very excited. “Yes, of course. Not only that, but as I recall what happened, I was quite surprised that the hurricane, violent though it was, had upset so many things. It could quite well be that someone took advantage of the storm to devastate the room and produce more damage than the wind could have done!”
“Who was the novice?”
“His name was Augustine. But he died last year, a fall from scaffolding as he and other monks and servants were cleaning the sculptures of the façade of the church. Actually, now that I think about it, he swore up and down that he had not left the door open before the storm. I was the one, in my fury, who held him responsible for the accident. Perhaps he really was not guilty.”
“And so we have a third person, perhaps far more expert than a novice, who knew about your rare poison. Whom had you told about it?”