1248-1298

French scholar and philosopher who was an early proponent of the theory of impetus. For centuries Aristotle's claim that a moving object requires continual application of force to keep it in motion had gone unchallenged. According to this explanation, wind and air themselves act as a form of propellant. The sixth-century Greek scholar Johannes Philoponus had posed the first notable challenge to this idea, but Olivi—soon followed by his countryman Jean Buridan—appears to have been the first scholar in Western Europe to do so.