Originally, a heckler was someone in the textile trade who combed out flax or hemp fibres.

Its more common meaning began in the early 19th Century when the radical and unionised hecklers working in Dundee used to interrupt the colleague responsible for reading out the day’s news. Hence the word became associated with firing off questions aimed to tease or comb out truths that the speaker might wish to conceal or avoid.

A more bawdy version had been practised much earlier, in Elizabethan theatre, where it was very much part of the boisterous atmosphere to shout at actors. An interruptive tradition that is – unfortunately for some – sometimes still practised today.

Not that heckling is confined to the theatre, it is a technique that is used in the political and scientific arena as well. In the following anecdote, the American biologist Daniel Dennett reminisces about a debate in which he sat alongside author Christopher Hitchens. Looking back, Dennett now believes sometimes a heckle is called for.

“We were both appearing in a debate as part of the program of Ciudad de las Ideas, an excellent gathering held annually in Puebla, Mexico. […] One of the speakers for the other side, the God side, was Rabbi Shmuley Boteach, […] the rabbi launched into a series of outrageous claims trying to besmirch Darwin and evolutionary biology by claiming that Hitler was inspired by Darwin to organize slaughters to ensure the survival of his race. I sat there, dumfounded and appalled, and tried to figure out how best to rebut this obscene misrepresentation when my turn came.

Christopher didn’t wait his turn. “Shame! Shame!” he bellowed, interrupting Boteach in mid-sentence. It worked. Boteach backpedaled, insisting he was only quoting somebody who had thus opined at the time. Christopher had broken the spell, and a particularly noxious spell it was.

Why hadn’t I interrupted? Why had I let this disgusting tirade continue, politely waiting my turn? Because I was in diplomacy mode, polite and respectful, in a foreign country, following my host’s directions for how to conduct the debate. But what Christopher showed me–and I keep it in mind now wherever I speak–is that there is a time for politeness and there is a time when you are obliged to be rude, as rude as you have to be to stop such pollution of young minds in its tracks with a quick, unignorable shock. Of course I knew that as a general principle, but I needed to be reminded, to be awakened from my diplomatic slumbers by his example.”

– Daniel Dennett