Et hoc scientes tempus qui hora est: Duration, timekeeping, university, and society in late medieval Paris

Kenneth C Mondschein, Fordham University


Medieval society was supremely well coordinated, with the ringing of church bells for the cycle of daily prayer serving as conventional signals. The question, then, is how Frère Jacques knew how to ring his bells. This dissertation argues that, from at least the early middle ages, these signals were based on astronomical observation, with a variety of devices such as water-clocks serving as observational aids—with the much more accurate astrolabe, which allows one to read the hour directly from the ascension of heavenly bodies, becoming common after the reintroduction of Ptolemaic geometrical astronomy. Chief amongst those who benefited from this knowledge were the scholars of the University of Paris. It was actually in the university environment that the idea of the fixed hour first took hold, and it was the academic community that was on the cutting edge of thought and of adapting the new technology to practical purposes. ^ This change in mentality was reflected in Scholastic philosophy, particularly commentaries on the fourth book of Aristotle's Physics. In discussions of what Aristotle meant when he defined time as "the number of the motion," we increasingly see between the thirteenth to the fourteenth centuries a break with an arithmetic conception of measurement of time and a shift to a geometric proportionality that mirrors the method of the astrolabe. Decades before clocks show up in chronicles or the fixed hour appears in work regulations, philosophers such as William of Ockham were comparing the heavens to a well-regulated clock—an irony, considering clocks were originally developed to minor the heavens as observational aids. Yet, this was only one thread out of many: Depending on their frame of reference, medieval people could equally consider time as a geometrical or an arithmetic proportionality. ^

Subject Area

Education, History of|History, Medieval|History of Science

Recommended Citation

Mondschein, Kenneth C, "Et hoc scientes tempus qui hora est: Duration, timekeeping, university, and society in late medieval Paris" (2010). ETD Collection for Fordham University. AAI3431916.