William of Ockham is best known today for the model of problem solving known as Ockham’s (or Occam’s) Razor. But the event that defined his life was an argument with Pope John XXII.
Research:

Behind the Scenes Minis: Carry-on Bags
28:38

Gustave Flaubert and the ‘Madame Bovary’ Trial
45:15

Elizabeth Bisland, Beyond the Trip Around the World
42:54