The Equilibrium Controversy
Guidobaldo del Monte’s Critical Notes on the Mechanics of Jordanus and Benedetti and their Historical and Conceptual Backgrounds
Two new sources related to this controversy are presented: an annotated copy of Jordanus de Nemore's "Liber de ponderibus" edited by Petrus Apianus in 1533 and an annotated copy of Giovanni Battista Benedetti's "Diversarum speculationum mathematicarum et physicarum liber" from 1585. Both works contain handwritten marginal notes by Guidobaldo del Monte, author of the most influential early modern text on mechanics.
A detailed analysis of these sources, their prehistory, and their contexts shows that the "equilibrium controversy" only scratched the surface of a much deeper conceptual crisis of early modern mechanics that was triggered by the introduction of the medieval concept of "positional heaviness" into early modern discussions. This crisis helped to establish fundamental insights on which Galileo eventually built his theory of mechanics as well as his theory of motion.