Natural Knowledge in the Latin Middle Ages 101From a quantitative point of view natural philosophy was more
than the heart of the university’s approach to the study of nature; it also
strongly infl uenced such related endeavors as academic medicine and the-
ology and even the philosophical courses in the studia of some mendicant
orders.^83 Its required texts were more numerous, and its lecture sequences
were often longer than those in the mathematical sciences, employing
more masters, generating more commentaries, and enrolling more stu-
dents. The universities thus set the tone for the way later medieval masters
practiced and advanced natural philosophy and, to a lesser extent, the
mathematical sciences as well.
How, then, was natural philosophy practiced? As its main task was
the critical scrutiny of assumptions, arguments, and conclusions about
all kinds of change, its cast was largely, but not exclusively, verbal. This
scrutiny, which was logic- intensive, took place both in oral disputations^84
and in written lectures, questions, commentaries, and expositions. Dispu-
tations, which centered on a particular question for example, “whether
the world is eternal”), were required of both students and masters. Student
disputations took place almost daily in some instances, before peers who
were penalized for failing to participate. The more sophisticated masters’
disputations were usually weekly events, which younger students were
also required to audit for two years.
In most fi elds, the disputation and the disputed question served both
to teach and to advance the state of knowledge. (As their medium, the
mathematical sciences often used the treatise rather than the question, al-
though exceptions do exist). Students witnessed the analysis of problems
from several points of view, with objections and responses, and encoun-
tered genuine disagreements among masters, who sometimes changed
their minds.^85 Although it was later stereotyped as empty haggling, mas-
ters valued the disputation highly as the road to truth. It earned the praise
of Jewish observers of the university, some of whom adopted its approach
in their own writings.^86 This oral culture left its mark on the texts of natu-
ral philosophy, often framed as disputed questions that spar with actual
or imagined opponents.
In this era, much “science was livresque” (bookish), “not just set down
in books; it was largely carried out in books.”^87 For Ockham at least, the
verbal cast of this enterprise was a principled position: “properly speaking,
naturalis scientia is not about corruptible and generable things, nor about
natural substances, nor about moveable things, for such things are sub-
jects or predicates in no conclusion known by naturalis scientia.”^88 Rather,
natural knowledge consisted of propositions, which in turn consisted of
words signifying things, concepts, and / or other words. It was the careful