The ancient philosopher Theophrastus described a gemstone called lyngurium, purported to be solidified lynx urine, in his work De lapidibus . Knowledge of the stone passed from him to other classical authors and into the medieval lapidary tradition, but there it was almost always linked to the 'learned master Theophrastus'. Although no physical example of the stone appears to have been seen or touched in ancient, medieval, or early modern times, its physical and medicinal properties were continually reiterated and elaborated (...) as if it did 'exist'. By the seventeenth century, it began to disappear from lapidaries, but with no attempt to explain previous authors' errors since it had never 'existed' anyway. In tracing the career of lyngurium, this study sheds some light on the transmission of knowledge from the classical world to the Renaissance and the changing criteria by which such knowledge was judged. (shrink)

It has long been shown that medieval builders primarily used geometrical constructions to design medieval architecture. The thought processes involved, however, have been considered to be remote from the natural philosophical speculations of the Scholastics, who, following Aristotle, had taken the basis of physics to be the study of dynamics, or change. However, investigations of the Expertises of Chartres, Florence, Milan, and other documents related to medieval building suggest that medieval architects, in speaking of their work, resort to recognizable dynamic (...) arguments, structured similarly to the speculations of Scholastic philosophers. These dynamic explanations of structural behaviour persist at least into the 17th century, but thereafter lost out to the arguments based on statics made by modern scholars attempting to explain the endurance of these structures. (shrink)