Knowing what an eminent scholar and celebrated theologian, he was, I was surprised that one legend attributes the "Dunce Cap" to him. It seems that King Philip IV of France wanted to tax the church in order to finance his war in England, but Pope Boniface VIII threatened to excommunicate him instead. Duns Scotus supported the pope and was banished from France. Those who disagreed with Scotus' teachings started referring to his supporters by the word 'dunce', which meant 'stupid or dull witted'. Duns' books on theology, philosophy, and logic were university textbooks. His followers were later challenged by their opponents about what was perceived as a system of hair-splitting and distinctions; their obstinacy over an increasing array of challenges posed first by humanists and then by reformers led to the term "dunses" to denote fools in general.
How ironic! The followers of Dun Scotus are dunces.