The fallacy of irrelevant humour is committed when jocular material irrelevant to the subject under review is introduced in order to divert attention away from the argument.
My opponent’s position reminds me of a story…
(Which will not remind the audience of the argument.)
While humour entertains and enlivens discussion, it also distracts. The fallacy does not lie in the use of humour but in its employment to direct attention away from the rights and wrongs of the matter in hand. A joke might win an audience, but it does not win an argument.
A member of parliament, Thomas Massey-Massey, was introducing a motion to change the name of Christmas to Christ-tide, on the grounds that mass is a Catholic festival, inappropriate to a Protestant country. He was interrupted by a member opposite who asked him how he would like to be called ‘Thotide Tidey-Tidey’. The bill was forgotten in the uproar.
The hustings heckler is the great exponent of this fallacy. His warblings accompany parliamentary election meetings, often drowning out any reasoned argument for the very good reason that they are a lot more interesting and quite often of a higher intellectual level. A few of them achieve the immortality of the book of quotations as ‘anonymous heckler’, especially if their interjection has prompted an even better reply from the candidate. Lloyd George, Winston Churchill and Harold Wilson all showed adroitness at turning a diversionary joke back upon its user.
QUESTIONER: What do you know about agriculture? How many toes pig?
NANCY ASTOR: Why don’t you take off your shoes and count them?
Often cited as a classic of irrelevant humour is the joke by Bishop Wilberforce when debating evolution against Thomas Huxley. Pouring scorn on evolution, the bishop asked Huxley:
You claim descent from a monkey; was it on your grandfather’s or grandmother’s side?
(Huxley’s reply is also considered to be a classic put-down. He saw no shame in being descended from a monkey, but described the man he would be ashamed to have as an ancestor; a man who despite his learning sought to obscure by means of aimless rhetoric and appeals to prejudice…)
The problem for the user of rational argument is that a guffaw is as difficult to refute as a sneer. The audience enjoys the entertainment more than the argument. A speaker for a religious sect would regularly invite his audience to supply any biblical quotation which conflicted with his view of things. When members of the audience obliged, as they often did, he would always reply:
That sounds more like Guinesses talking than Genesis.
(The volunteer was invariably discomfited by the gale of laughter.)
Those who set out upon the trail of public debate should carry a knapsack full of custom-built jokes ready to toss before an audience in times of need. At the very least, the wave of mirth washing over your victim slightly lowers his authority, even while it gives you time to think.
The ability to produce irrelevant humour on the spur of the moment is a product of wit and experience. Many years spent in the debating chamber of a university will sharpen your ability to think on your feet. The joke need not even be a clever one if delivered with style. I once saw a speaker making a perfectly valid point about sales to authoritarian states of airplanes which could carry nuclear weapons. He was floored by an interjection which suggested that wheelbarrows could do the same.
An undergraduate in the process of being censured for high crimes and misdemeanours took all of the force out of the attack by facing his audience solemnly and saying:
I wish to accept censure, and to couple with it the name of my mo who also thinks I’ve been a very naughty boy.
(Collapse, amid uproar, of prosecution case.)