A dunce is a person considered incapable of learning. The word is derived from the name of the Scholastic theologian and philosopher John Duns Scotus, also referred to as Doctor Subtillis, or "Subtle Doctor", whose works on logic, theology and philosophy were accepted textbooks in the universities from the fourteenth century.
Duns or Dunsman was a name applied by early opponents to the followers of Duns Scotus, who were less disparagingly called the Scotists. When in the sixteenth century the Scotists obstinately opposed the new learning (i.e., the King James Bible), the term duns or dunce became, in the mouths of the Protestants, a term of abuse and a synonym for one incapable of scholarship. This was the etymology given by Richard Stinhurst. Samuel Johnson, on the other hand, maintained that the source of the word was unknown.
Dunces are often comedically shown wearing paper cone hats, known as dunce caps with the word "dunce" or "dumb", or simply a capitalized "D" on them. Schoolchildren were sometimes compelled to wear a dunce cap and to sit on a stool in the corner as a form of humiliating punishment for misbehaving or for failing to demonstrate that they had properly performed their studies.
The word "dunce" comes from John Duns Scotus (c. 1266–1308), the Scottish Franciscan scholar who, with Thomas Aquinas and William of Ockham, was one of the leading Scholastic philosopher-theologians of the High Middle Ages. Duns Scotus wrote treatises on theology, grammar, logic and metaphysics which were widely influential throughout Western Europe, earning Duns the papal accolade Doctor Subtilis (Subtle Teacher). (Duns remains highly esteemed in the Roman Catholic Church, and was beatified by Pope John Paul II in 1993.) However, with the advent of the Renaissance and the New Learning, and then the Protestant Reformation, many of Duns's theories and methods (which were considered hair-splitting) were challenged or rejected by Humanist and Protestant scholars, who used the term "Dunsman" or "Dunce" in a pejorative sense to denote those who foolishly clung on to outmoded doctrine. (The form "Dunce" reflects the medieval pronunciation of "Duns".) Gradually "dunsman" or "dunce" was used more widely for anyone stupid or dull-witted.