Mumpsimus

Mass at Fatima, Portugal

One of the strangest, if not weirdest, words that you can find in many English dictionaries is “mumpsimus”. It looks like Latin, but everybody who knows a little Latin and has a feeling for the language, knows that it cannot be Latin, nor cannot it be an original English word. But what then can the origin of this word be?
I didn’t know the word, until I read a biography of the great Dutch theologist and philologist Desiderius Erasmus (1466-1536). One of the tasks Erasmus had set himself was making an improved edition of the New Testament. In the days of Erasmus the Bible version used by everybody was the so-called Vulgate. The origin of the Vulgate goes back to the fourth century. After intensive study of the Vulgate it had become clear to Erasmus that the book was full of mistakes. The origins of these mistakes were many. For example, the original books of the New Testament were in Greek, but the Vulgate is in Latin, so it’s a translation of the original. Moreover, when the Vulgate had been written, already several versions of the Greek Bible books existed, and they were all a bit different. The question then is: What is the real original text? Also important was that the Vulgate was already more than thousand years old and it had been copied by hand again and again. Especially this was a source of many mistakes. And last but not least, for several reasons sometimes sentences had been added to or omitted from the Vulgate during these thousand years. Erasmus decided to try to reconstruct the New Testament in order to get a text that was as near to the original as meant by the authors as possible. He called the result Novum Instrumentum (New Instrument). The Novum Instrumentum contained the original reconstructed Greek text of the New Testament, a Latin translation and an extensive explanation of both, so that the readers could judge themselves whether Erasmus had made the right choices when reconstructing and translating the New Testament.
When Novum Instrumentum was published in 1516 Erasmus was sharply criticized. However, it was not because the Erasmus should have made the wrong choices in his text reconstruction, but he was criticized because he had reconstructed the Vulgate. People were angry because Erasmus had replaced old familiar words by new words. There were even rumours that the Novum Instrumentum would be judged by the Inquisition, the court of the Roman Catholic church. This made Erasmus in a letter to a friend refer to a story going around in his days “about a poorly educated Catholic priest saying Latin mass who, in reciting the postcommunion prayer Quod ore sumpsimus, Domine (meaning: ‘What we have received in the mouth, Lord’, instead of sumpsimus (meaning: ‘we have received’) substitutes the non-word mumpsimus ... After being made aware of his mistake, [this priest] nevertheless persisted with his erroneous version, whether from stubbornness, force of habit, or refusing to believe he was mistaken.” (quoted from the Wikipedia) The theologians who judge my Novum Instrumentum, so Erasmus, are like this priest who didn’t recognize and correct his mistake, even after it had been explained to him. When former students of Erasmus in Cambridge heard about this letter, it caused such great hilarity among them that since then “mumpsimus” became an expression for nonsense, inveteracy and for an inveterate person in the English language, an expression that still exists in modern English. So we can say “He prefers his mumpsimus for my sumpsimus”, meaning that he stubbornly sticks to a clear mistake that I have explained to him. Generally, a “mumpsimus” is a person who adheres to or persists in old ways or ideas, practices, uses of words, etc., although it has been made clear that they are wrong, erroneous, etc. Also the practice, idea etc. itself can be called a mumpsimus. A modern example of a mumpsimus is the former American president George W. Bush, who persisted in saying “nucular”, when meaning “nuclear”. And I would call also many anti-coronavirus-vaxxers mumpsimusses, in view of all the facts that have shown the value of vaccination against Covid 19. On the other hand, one shouldn’t be too hard on someone who is a mumpsimus, especially when it is on matters that aren’t really important. Aren’t we all often mumpsimusses? Don’t we all often stick to ideas, habits, practices and so on, which we once thought reasonable if not good but which have shown to be mistakes, false ideas, bad habits …? Many people often make themselves immune to criticism, just because they don’t want to change, just because they don’t like the person who criticizes them, just because going on in the old way is easier than changing, despite the negative consequences. Is not everybody a mumpsimus in his or hear heart? Everyone thinks his own geese swans. 

Source
Sandra Langereis, Erasmus dwarsdenker. Een biografie. Amsterdam: De Bezige Bij, 2021; pp. 542-544.