Projectile Motion in a Vacuum According to Francesc Marbres, Francis of Marchia, Gerald Odonis, and Nicholas Bonet

In the third decade of the fourteenth century, the first definitive steps were taken to replace Aristotle’s theory of projectile motion and to apply the new theory to explain finite motion in a vacuum. The main actors in this shift were the Franciscan theologians Francis of Marchia, Gerald Odonis, and Nicholas Bonet, as well as Francesc Marbres, the artist formerly known as ‘John the Canon,’ but there is some confusion about their respective roles. Over the past decade, critical editions and manuscript studies of the pertinent texts of Marchia, Odonis, and Marbres have provided the raw materials to straighten out what some have considered the early background to the Galilean theory of projectile motion.