The Herbs

The Herbs are a recurring motif in the abbey, used both for legitimate medicinal purposes by the herbalist Severinus and for illicit, manipulative ends to induce terrifying visions and protect the library's secrets. They represent the dual potential of knowledge—to heal or to harm, and are a key instrument in the psychological defense of the labyrinth.

Nature and Legitimate Use

Severinus of Sankt Wendel, the brother herbalist, maintains a rich garden and laboratory stocked with a vast array of simples, many of which are both medicinal and potentially lethal. He explains that the line between poison and medicine is very fine, noting that the Greeks used the word "pharmacon" for both. His collection includes substances like valerian, which in small doses calms the heart but in exaggerated doses brings on drowsiness and death, and mandragora officinalis, which is good for sleep but also known to stir desires of the flesh. He also keeps a highly powerful, slimy yellowish poison given to him by a traveling brother, which he was advised not to touch, as it could kill in a short time if it came into contact with the lips. This poison was later stolen, likely by someone who took advantage of a storm to create confusion in the infirmary.

Illicit Use for Visions

The herbs are also weaponized to protect the library. Nicholas of Morimondo, the master glazier, explains that certain substances can be used to grease the wick of an oil lamp, and the fumes produced then provoke visions. He describes how taking the wax from a dog's ear and greasing a wick can make anyone breathing the smoke believe he has a dog's head, and how with the eyes of a bat and the venom of a wolf, one can make a wick that causes the viewer to see the animals whose fat has been taken. These techniques are employed in the library to convince intruders that it is guarded by diabolical presences. When Adso enters a room where such a lamp is burning, he experiences a terrifying vision of a dragon, a woman, and Berengar, and his hands seem to grow out of all proportion. William later identifies the odor and explains that the herbs are only herbs, requiring none of the necromantic preparations the glazier talked about, and that they simply cause the subject to develop what they have glimpsed in a book and let their own desires and fears speak out.

Connection to the Crimes

The herbs are directly linked to the series of murders. The stolen poison from Severinus's laboratory is used to coat the pages of the forbidden book, Aristotle's Poetics II. Venantius of Salvemec, after stealing the book, avidly leafs through it, and the poison on his fingers and tongue leads to his death. Berengar of Arundel, who later takes the book, dies in the same manner, his tongue blackened. The poison is described as having "the power of a thousand scorpions," a phrase Jorge of Burgos uses to warn Malachi of Hildesheim. The herbs thus become the instrument of a calculated murder plot, transforming a tool of healing and psychological defense into a weapon of lethal knowledge.