It is frustrating that the name of one of Scotland's greatest thinkers has become derogatory slang for a poor learner. John Duns was the brilliant 13th-century thinker and scholar whose provocative ideas so annoyed his intellectual opponents that they sought to discredit him by using his name to signify stupidity. "Duns" evolved into "dunce" and became a term of contempt in classrooms around the world.
Fortunately, progress has been made. Many teachers have figured out that such labels are unhelpful and that progress in learning is more likely to be achieved by encouragement and positive reinforcement than disparagement.
But the term is still around, encouraging self-doubt and undermining the confidence of learners. "James is a real dunce at school," I recently heard an unthinking mother say to her friend as the poor boy listened in.
Politicians don't always help, either. At a recent Prime Minister's Questions (which is surely more unruly than most of our classrooms), the leader of the opposition called the prime minister a dunce. That a senior national figure should use such language on a national stage is frankly disappointing.
A lack of confidence is at the centre of much of the underachievement we see in our schools today. Instead of self-esteem being boosted, it is all too often crushed and destroyed by a relentless stream of damaging remarks and put-downs that cause learners to become disillusioned.
It is, to me, quite obviously wrong for a pupil's page of writing to be defaced with red ink and crosses. Instead, a thoughtful teacher will pick out and highlight two good things about the text and one thing that could be improved. The "two stars and a wish" approach - or "sandwich" as I have heard it called in the US - both supports and motivates our younger learners.
For some pupils, low in self-esteem, "five stars and a wish" is an even better method. Throughout my career I have encountered too many pupils who are reluctant to write or contribute to discussions because they are terrified of being wrong and appearing stupid.
Self-defeating prophecies are particularly prominent in maths. Many learners are quick to assert that they are dunces when it comes to dealing with numbers. Positive marking goes some way towards boosting confidence and encouraging original thinking. Achievement, after all, is often the consequence of steady increases in aspiration.
And it is not just individuals who become disillusioned by constant negativity. Entire classes of poor achievers disengage once they realise that their group constitutes the school's bottom set or the "dunce section".
It's not just admirers of the great John Duns who should be disappointed by this but our entire education system.
John Greenlees is a secondary school teacher in Scotland