Arrival and Deduction of Brunellus

On the morning of the first day, as William of Baskerville and his novice Adso of Melk ascend the steep path to the abbey, William pauses at a crossroads where the main path divides into three. Without having seen any horse, he announces to the cellarer, Remigio of Varagine, that the abbot's favorite horse, Brunellus, has taken the path to the right and will be found near the dungheap. The cellarer, who had been searching for the horse, is astonished, and when his men soon return leading the animal by its halter, William's reputation for great acumen is instantly established among the monks.

The Deduction

William later explains to Adso the chain of reasoning that led to his conclusion. At the crossroads, fresh hoofprints in the snow indicated a small, round hoof and a regular gallop, suggesting a well-bred horse moving calmly. Where evergreen pines formed a natural roof, twigs had been freshly broken at a height of five feet, and a blackberry bush still held long black horsehairs from a swishing tail. The path to the right, William deduced, led to the dungheap, as he had noticed the spill of waste down the cliff below the east tower. From these singular traces, he inferred the passage of a specific horse.

The Name and the Authority

When Adso asks how William knew the horse's name was Brunellus, William explains that the cellarer himself had undertaken the search, indicating the horse was the finest in the stables. A monk who considers a horse excellent, William notes, will describe it according to the authorities, such as Isidore of Seville, who prescribed a small head, sharp ears, and big eyes. Furthermore, the great logician Buridan always used the name Brunellus for a horse in his examples, a fact William knew the learned monks would follow. Thus, William's knowledge encompassed not only the book of nature but also the way monks read the books of Scripture and how they thought through them.

Significance and Method

This episode establishes William's method of reasoning: he collects particular data—hoofprints, broken twigs, horsehairs—and from them infers a general law, which he then tests against the specific situation. He acknowledges that his initial reasoning brought him close to the truth, but full knowledge came only when he saw the single horse. The event also reveals William's vanity in demonstrating his acumen, as he deliberately slows his pace to allow the monks to precede him and spread word of his skill. This display of intellectual prowess, grounded in empirical observation and knowledge of scholastic tradition, defines William as a detective who reads the world as a great book, a skill that will prove crucial in the days to come.