There is no easy means of knowing whether Jarvis Cocker had that old and uncomfortable Jewish saying in his head before he jumped up on to the stage at the Brit Awards last month to protest about Michael Jackson's blasphemous poncing around.
The pop music business has a long history of these rushes of blood to the head, or what the existentialists used to call "gratuitous acts". Remember Grace Jones belting poor Russell Harty, of all people? And no one could ever know exactly what John Lennon, or the Stones, or the Sex Pistols were going to do.
Some of this, of course, was hype just as calculated as Michael Jackson's. But whether Jarvis Cocker planned his explosion or just lost his rag, he has certainly added his name to the long and heartening list of those who have suddenly made up their minds that someone or something had gone too far.
Sometimes it is a stand on high principle. "Give me liberty, or give me death," said Patrick Henry, the first American governor of Virginia and the chief author of the Bill of Rights, or so at least says his hagiographer, William Wirt.
Sometimes it is a sense that pomposity or flattery cries out to be pricked. Even Louis XIV, not famous for his humility, felt that a courtier had gone too far when he compared, "not the king to God, but God to the king". "Too much, monsieur," was the monarch's murmured rebuke, "is always too much."
It can be Oliver Twist asking for more, or Brian Clough suddenly punching a loud-mouthed spectator, or Eric Cantona kicking ass. Sometimes, if the act seems excessive, you have to remember that it is a reaction, not so much to the final excess, but to earlier provocations that passed unpunished.
Sometimes the act is dramatic but pointless and without consequence, like Matthias Rust's crazy flight to Moscow. He passed unscathed, perhaps unnoticed, through the Soviet air defence system and landed his light aircraft in Red Square. Embarrassed, the Russians kept him in jail for a while, then kicked him out.
But sometimes an individual's momentary loss of patience expresses what millions are feeling. Then great historical processes, sweeping nations along in their course, can be traced to the action of a single individual on the spur of the moment.
Or so I like to believe. Marxist and post-Marxist historians brush such occasions away as trivia, mere "events"; and, if you want to hear scorn poured into a word, listen to a French historian - or one of his Anglo-Saxon disciples - pronounce the word "event".
Would the French Revolution itself have happened if Camille Desmoulins had not clambered on to a table outside the Cafe Foy in the Palais-Royal on the afternoon of 12 July, 1789, stuck a green leaf in his hat band, and shouted, "To arms!" Probably. But this was the way it did begin. The crowd milled out into the street, its "ultimate destination" the Bastille.
Would the civil rights revolution have happened in the American South if an elderly seamstress called Rosa Parkes hadn't been told to move to the back of a city bus in Montgomery, Alabama? Mrs Parkes, so the legend goes, was "sick and tired of being sick and tired of being sick and tired". Certainly her feet hurt.
She refused to budge. So the bus driver arrested her, the black community boycotted the buses, and in the ensuing upheaval Martin Luther King became a world figure. Would it have happened anyway? Perhaps. But the way it did happen began with Rosa Parkes.
Nor is it always the people who will be endorsed by history who suddenly decide they have had enough. On the eve of the American Revolution, British soldiers were often so badly paid that they had to ask American employers for work. "Soldier," asked rope maker William Green of Private Patrick Walker, who was walking by, "do you want work?"
"Yes, I do, faith", said Walker.
"Well," said Green, "then go and clean my shithouse."
The exchange led to a scuffle, and later to five deaths, in what Americans called the Boston Massacre. Private Walker's understandable anger had its consequences, but hardly the ones he had in mind at the time.
Sometimes the act of defiance demands even more courage than Rosa Parkes displayed. The world remembers the solitary figure kneeling in front of the tanks in Tiananmen Square.
Often it is suicidal. On 15 January, 1969, a Czech student, Jan Palach, was dropped off from a car by his friends in Prague's Wenceslaus Square. He doused himself with petrol and burned himself to death. His death may have seemed pointless, wasted. But 20 years later, demonstrations to commemorate his act helped to trigger off the Velvet Revolution against the regime he had despaired of bringing down.
In Andre Malraux's The Human Condition the student, Chen, philosophises about the gratuitous revolutionary act as he waits to throw his bomb. The 20th century has been dangerously obsessed with the poetry of the deed, the existential meaning of the bullet or the bomb.
Most such acts are not really gratuitous at all. A committee of bullies with excellent arguments why they should not throw the bomb themselves plan for months before the young foot soldier throws it and either blows himself up or lands himself 20 years in jail.
Emily Davidson did not suddenly decide to throw herself under the King's horse in the Derby, and Gavrilo Prinzip did not shoot the Archduke Ferdinand in Sarajevo in a sudden fit of temper. True, up to the last moment they had a choice. They could have decided not to commit the decisive, the irreversible, act. But to do that would have been to go back on a commitment and to betray co-conspirators.
Sudden acts of rage and violence, with their power to create a new political reality for good or evil, have helped to plot the course of the 20th century. Some of them were horrifying, some heroic. There were, after all, at least six attempts to assassinate Hitler.
And such acts are not new. Despite the knowledge that they risk being put to death in horrible ways, there have always been assassins ready to strike at those they consider tyrants. And there have always been Luthers, daring to nail their theses to cathedral doors, and Galileos, insisting under their breath, "But it does move!"
So, even if he ran no risk of being burnt alive, or even being beaten to a pulp, let us salute Jarvis Cocker for his gratuitous deed of rebellion against the monstrous tyranny of hype
Signs of the times
From Sixties flower power to lesbians abseiling into the House of Lords, these are acts which have captured the public imagination
October 1967. It was the biggest anti-Vietnam demonstration to date, one of the defining moments of the Sixties, perfectly encapsulated by the hippies who thought the way to change the world was by poking a flower down the barrel of a gun. Organised by the the National Mobilization Committee to End the War in Vietnam, known as "The Mobe", 55,000 demonstrators picked up their petals, gathered at the Lincoln Memorial in Washington, DC, and marched on the far enough, so with the full force of flower power behind them, some hippies tried to levitate the bastion of the US armed forces three feet off the ground. Many were arrested after clashing with the authorities, but the March on the Pentagon, as it came to be known, inspired one of the classics of protest literature, Norman Mailer's Armies of the Night. Matt Hoffman
Black day for sport
In the Mexico Olympics of 1968, the gold and bronze medals in the 200 metres both went to black Americans, to Tommie Smith and John Carlos. They stood on the winners' rostrum, their chins sunk on their chests, to which were pinned buttons announcing "Olympic Project for Human Rights"; as the first strains of the Star-Spangled Banner sounded, their black- gloved fists shot out in a gesture of defiance against their country and solidarity amongst all blacks.
It was a moment which captured how the tide of race and racism had burst the banks of sport and nationalism, and how the tone of the American civil rights movement had turned aggressively dissonant. No one now outside athletics remembers Smith and Carlos, but their salute is an abiding image of the Mexico Olympiad. Robin Crowther
Westwood's bottom line
We all knew she would wear something outrageous to pick up her OBE from the Queen on 15 December, 1992. She had recently riveted the nation by primping on Dame Edna Everage's TV show wearing only a nude body with a sewn-on fig leaf. The queen of the mini-crini, with her bottom-enhancers and nine-inch platforms, said later that she simply forgot she was knickerless. So when the photographers asked Viv to give them a twirl at the palace gates, she raised her skirts and gave them a full-frontal flash.
Her candour was too great even for the British press."She wasn't the slightest bit embarrassed," mumbled one horrified hack. "Outrage! Knickers shock at royal do!" yelled the papers the next day, tastefully doctoring shots of the infamous moment with a suitably positioned crown.
But La Westwood had no time for silly posturing. "I hardly ever wear knickers," she explained, "even when riding my bike. I find them constricting. And I never have time to buy any I like." In fact, she continued, she would like to help the Queen dress a little, well, better. So there. Rosie Millard
The Lizard of Oz
When the Queen visited Australia in early 1992, Paul Keating, the Labour prime minister, put his hand around her waist as he guided her through an official reception in Canberra. No sooner were the pictures of Keating's gesture beamed back to Britain, than all hell broke loose. Keating was denounced as "the Lizard of Oz", the uncouth Irish Catholic nationalist with no respect for royal protocol, the Republican who dared to touch the Queen.
It was a defining moment in Britain's perception of Keating as an iconoclastic colonial. In Australia, where protocol is less rigidly observed, Keating's gesture barely created a ripple. It was interpreted more as a polite gesture towards someone held in high regard, rather as one might protectively guide one's aunt through a room of strangers. The outcry in Britain bewildered most Australians, and even Keating's political opponents have never used the issue to attack him: it was a political non-starter.
Keating remains an ardent Republican, but his Republicanism stems more from deep-seated convictions about Australia's future than from any antipathy towards the royal family. When the Prince of Wales visited Australia two years later, he was asked if he'd been offended. "No," he said. "Neither was the Queen." Robert Milliken
Clough clips your ear
When Brian Clough laid into five Nottingham Forest fans who ran on to the City Ground pitch after a match in January 1989, it wasn't the first time he had acted symbolically, as though he were patriarch of the nation's dysfunctional family.
If he saw some boys misbehaving in the street when he was driving home, he would stop the car and smack their heads and say, "Tell your dad that Brian Clough clipped your ear, and if he wants to see me about it, he knows where I live." Mr Clough thought he was the dad that every kid ought to have. Many dysfunctional parents would have liked him to manage their own children.
Ornately courteous and deferential towards women, he subordinated men to his authority, calling them all "young man", even if they weren't. He told his players, especially his own sons, what to wear, what to eat and who to marry. He told journalists what to write, and tried to tell the country what to think. He always knew everything and knew best. He liked to be known as the Boss. Just like Dad.
But the Boss also liked a bung, according to the England manager, Terry Venables. The reason he did not make much sense was that he was sozzled with booze most of the day. The Boss was barmy. When he apologised to the boys he had punched, he also demanded a kiss from them. It never occurred to him that they might have reason to punch him. Neil Lyndon
Gazza books the ref
New Year's Eve in Glasgow, and the Hogmanay spirit is abroad as Rangers are thrashing Hibernian 7-0 at a packed Ibrox Park. However, the bonhomie bypasses the referee, Dougie Smith. As half-time approaches, he drops the yellow card, symbol of his authority. This is picked up by Gazza, the lovably wayward superstar, who waves it in Mr Smith's face before handing it back with a cheeky grin - a moment of spontaneity which has more than 44,000 people chuckling along.
For Gazza, read William Brown; for the yellow card, read the cane - and for Dougie Smith, ol' Marky, his humourless teacher. Mr Smith "caned" Gascoigne. The card was immediately shoved back in his face, and his name was jotted in the referee's book. Gazza smiled as he walked away from his beating, the smile of someone who knows full-well the cost of a good gag, which is generally a price worth paying. Nick Donaldson
The floor of the House of Commons is the closest that British public life comes to a sacred space, where a violation of the rules is blasphemy and the punishment must be terrible. Those implements of arcane purpose which sit on the table in front of the Speaker must never be touched, except by those magically entitled. They must certainly not be brandished by an Opposition MP when the government's backbenchers are singing triumphantly late at night; yet Michael Heseltine was not struck down for his boldness one night in 1978 when he picked up the mace as a gesture against the arrogance of the Labour MPs opposite.
The hour was late. All the observers were excited, and some may not have been wholly sober. Everyone agrees that he lifted the mace; and that the act in itself would have been blasphemous enough to have brought the Commons to a halt. But his feat grew in the re-telling. Did he swing it, once lifted? Did he brandish it? Did he whirl it round his head, uttering wild ululations?
The answer to the last question is, certainly not. Yet that, or something like it, is the memory left with the public. It was not the breach of the Commons rules that mattered, but the force of the personality that had breached them. Andrew Brown
The spirit of Lady Godiva
During a thanksgiving service in January this year to mark the centenary of the British motor industry, a woman protester calling herself "Angel" stripped naked beneath the altar of Coventry Cathedral. She launched her anti-car protest alongside mothers dressed in black holding photographs of children killed in road accidents.
"In the spirit of Lady Godiva," she shouted, just as the Provost began reading the litany of reconciliation, "I am here to mourn the death of my mother and the 17 million people killed directly by the motor car - to remember the mothers left childless, the orphaned children, those paralysed and maimed, and the epidemic of asthmatic children."
A congregation which included MPs, industrialists and Prince Michael of Kent were greeted with shouts of "murderers". They heard the Bishop of Coventry describe the motor car as a liberating force, but one that had also caused great misery. Sophia Chauchard-Stuart
Lesbian rope trick
February 1988. Militant lesbians abseiled from the public gallery on to the floor of the House of Lords. They were protesting at their lordships approving Clause 28 of the Local Government Bill, which restricts promotion of homosexuality by local authorities.
The four women, part of the Stop the Clause Group, shinned down ropes into the arms of Black Rod, Air Chief Marshall Sir John Gingell, and a group of ushers, crying "Lesbians are angry", "It's all right for you, you don't have to live with it", and "How could you vote for this Bill?"
Later, the lesbians broke into the BBC's news studio and chained themselves to the desk of Sue Lawley, the presenter of the Six O'Clock News, while the programme was on the air. Lawley continued reading the news while her co-presenter, Nicholas Witchell, sat on the head of one of the protesters with his hand over her mouth. Viewers heard Lawley announce, "We have rather been invaded", and then various muffled shouts and thumps, and the camera began to shake. Sophia Chauchard-Stuart
The Duchess of hearts
It was in front of a packed Centre Court at Wimbledon, after the women's final four years ago, that the Duchess of Kent comforted the weeping Jana Novotna with an unforgettably tender gesture. She took the head of the beaten Czech girl and cradled it for a moment against her shoulder, stroking her hair in a gesture of consolation. Although it happened in front of a crowd of many thousands, it was still a private moment, an act of unmistakable spontaneity.
The Duchess of Kent has always been content to be a low-key royal. Katharine Worsley married the Duke in 1961, in the days when a "commoner" meant someone untitled, albeit from an ancient county family. The Duchess has been an utterly non-spectacular royal: gentle, modest, intelligent, always correctly dressed, never showy; in a word, the very best sort of pre-feminist woman - indeed, one of that almost vanished species, a lady.
After many years of marriage, it became known that the Duchess was suffering from clinical depression. She never asked for public sympathy, just coped in a quiet way. The experience probably gave her that instinctive, unforced generosity which made her react so immediately to a loser's grief. And because we knew it was totally genuine, we loved them both for it. Angela Lambert