Can a lump of stone cause disasters? Definitely, according to the Christians of Carlisle. They recently petitioned their local council - unsuccessfully - to dismantle a sculpted granite 'Cursing Stone', claiming that it was bringing the town misfortune on a biblical scale. The 14ton boulder, created by artist Gordon Young as part of the city's millennium celebrations, is carved with a 1069word curse invoked by the Archbishop of Glasgow in 1525 on lawless crossborder families known as the 'reivers'. "I curse their face, their brain, their mouth, their nose, their tongue, their teeth, their forehead"

Ever since the artwork was installed, Carlisle has suffered floods, foot and mouth disease, a fire and, possibly most ravaging of all, the relegation of the local football team. So obviously it must all be the fault of the stone. It's just the kind of logic employed by mediaeval pardoners flogging pigs' bones as holy relics.

Not that cursing is confined to Christians. Belief in its efficacy lies deep in human consciousness, associated with many different versions of the supernatural all over the world.

Voodoo dolls are probably the most ubiquitous agents of curses. The hexer creates a small effigy of the enemy, usually out of wax, and incorporates a small item belonging to the victim, such as a lock of hair or fingernail clipping. The doll is then stuck with pins  and monstrous misery unleashed.

But not everyone needs effigies to do their dirty work. In China a curse can be delivered by simply leaving a few grains of rice and a few pennies on the victim's doorstep, symbolizing a wish that the victim be stricken with poverty. With rather more civil service efficiency, the Romans inscribed the names of their hex victims onto thin metal sheets, which were then rolled up and pierced by nails.

Curses were routinely used as a deterrent against tomb raiders in ancient Egypt, as the Earl of Carnarvon and Howard Carter discovered when excavating Tutankhamun's burial chamber. They found an inscribed clay tablet which read: "Death will slay with its wings whoever disturbs the peace of the pharaoh." Six months later Carnarvon died of an infected mosquito bite, and six other members of the team suffered similarly untimely endings.

The Carlisle installation has its roots in an ancient Irish tradition of stroking a stone until it was thought to have absorbed the forces of hatred. Gems and crystals have also frequently been thought to possess diabolical powers. The Hope Diamond purchased by Louis XIV from Tavernier in 1668 is thought to be cursed because so many of its owners have suffered illness and untimely death.

Hexes and curses in many cultures are an accepted part of daily business. If you wish to avenge a wrongdoing you simply pay the local shaman or witch doctor to invoke the spirits on your behalf. There is no guarantee that it will work, but victims may well fall ill or make poor decisions simply through the powerful agency of suggestion. In the digital age it's much easier to invoke a curse, or to have one lifted. All you need to do is email any number of eager hexers, supply your credit card details, and you're away.

Take Bogdan Ravaru and Giancarlo Cappucio, for example. "It's not a coincidence that you got to this page. You're here to change your life in miraculous ways!" promises their website, which offers a special introductory deal of three free spells to anyone who subscribes to their cursing service. Or you can invest in Gurudev's Special Talisman, guaranteed to protect you from black magic and curses.

These entrepreneurs are virtual descendants of the witches of the Middle Ages, who would perform the most unpleasant enchantments for a modest consideration.

This kind of transaction has always made the Church uneasy, because it exposes a fundamental split between Catholics and Protestants. Catholics are comfortable with cursing because they recognise the ability of priests to call upon divine power. Indeed, the Carlisle curse was originally approved by the then pope and was read out loud in every parish after he had visited the area and pronounced it "the most lawless place on earth".

But it's a lot more disturbing for Protestants. In his magnificent work Religion and the Decline of Magic, Keith Thomas describes how the Lollards, the architects of the Reformation, tried to ban cursing altogether, regarding it as too closely associated with witchcraft and superstition. Since they rejected the notion that an intercessor was needed to appeal to God, they also rejected the special gifts assumed by Catholic clergy. For them, the whole idea of calling in the Lord's spiritual troops smacked of impertinence.

But the Lollards were only partially successful in their crusade to separate religion from magic. For a start, there's the JudeoChristian conviction that mankind has been cursed by God as a punishment for original sin. So cursing was strongly believed to work, because it invoked the consequences of transgressing God's laws.

Paradoxically, though, although cursing was seen as an expression of divine will, the majority of those who claimed these powers were considered to be servants of the devil. So the righteous curses of the clergy would be at perpetual war with the dark machinations of Satan. His agents on earth would therefore need to be exposed and eliminated. Which explains the persecution of witches, who in Christian iconography were the embodiment of evil.

This belief was often shared by witches themselves who, downtrodden and stateless, willingly embraced the delusion of power that came with malignity. And their fantasies would have been fuelled by the longheld conviction that the most effective curses came from the most poor and oppressed. The legend of the Beggar's curse  against those who refused to give alms  held currency right up to the 19th century.

As Keith Thomas explains: "The idea that God would avenge all injuries, and that moral retribution was to be found in this world no less than the next, was the justification for the curses and maledictions which were such an enduring feature of 16th and 17th century village life." He goes on to cite numerous examples of the most disadvantaged and wretched falling to their knees to utter public imprecations, calling on God to consume their enemies with fire, plague, barrenness and blight.

Shakespeare's most virulent cursers are always the most oppressed and powerless. Caliban, in The Tempest, is berated by Prospero for blasphemously abusing the language he has learned. But his are cries of impotent despair against the master who has enslaved him. Even more elaborate are the curses uttered by the degraded, outwitted, savagely abused women in Richard III  like the twice bereaved Margaret, who spits out an avalanche of invective at the murderer of her husband and now her son:

The worm of conscience still begnaw thy soul! / Thy friends suspect for traitors while thou liv'st, / And take deep traitors for thy dearest friends!/ No sleep close up that beady eye of thine, / Unless it be while some tormenting dream / Affrights thee with a hell of ugly devils! / Thou elvishmarked, abortive, rooting hog!

They may not quite aspire to the explosive rhetoric of Shakespeare, but every oppressed minority has its own rich stock of curses. "May she marry a ghost and bear him a kitten, and may the high king of glory permit it to get mange," chant the Irish, who must be among the high priests of creative cursing. "May the curse of Mary Malone and her nine blind illegitimate children chase you so far over the hills of Damnation that the Lord himself can't find you with a telescope."

But that's practically Shakespearean compared with the imprecations used by Arabs against their enemies. "May the fleas of a thousand camels infest your pubic hair," or "may your left ear wither and fall into your right pocket."

Similar anatomical dislocations preoccupy the Jews, with their wishes that their enemy's buttocks should fall off, that leeches may drink him dry, onions grow in his navel and, perhaps incorporating all of these: "He should give it all away to doctors."

Among the most renowned cursers, and the most dispossessed, are gypsies, who are given to utterances like: "May you wander over the face of the earth forever, never sleep twice in the same bed, never drink water twice from the same well, and never cross the same river twice in a year." And the more existential: "May you have a lawsuit in which you know you are in the right."

Michael Howard's ears must be scorching. Not to mention the rest of the Howards. Because the most powerful curses are invoked not just against an individual but against families or tribes  like the house of Atreus in Greek myth, which suffered a spectacular succession of patricides and matricides following the curse of the gods, or those Carlisle reivers who caused so much mayhem on the Scottish borders.

Prince Rainier, who has just died of natural causes at the age of 81 after marrying a glamorous Hollywood star and ruling Monaco for 56 years, doesn't appear to have been too badly damned. But he no doubt blamed the libidinous antics of his daughters, not to mention the single and childless status of his only son, on the curse inflicted on his family in 1297 after the first Grimaldi, Francesco the Spiteful, tricked the principality's defenders by disguising himself as a monk seeking sanctuary, only to slaughter them.

But the most persistent contemporary example of a family curse, intermittently revived by the media, relates to the Kennedy clan. According to Edward Klein, in The Kennedy Curse, the patriarch Joseph Kennedy was travelling home on an ocean liner in 1937. Also aboard was Israel Jacobson, a poor Lubavitcher rabbi, and six of his Yeshiva students who were fleeing the Nazis. When Kennedy complained to the captain about the noise they made praying on Rosh Hashanah and forced them to be silenced, the Rabbi damned Kennedy and all his male offspring to tragic fates.

Kennedy wasn't the first president to be bewitched. The Algonquin tribe of Native Americans once proclaimed that every 20 years after 1820 a president would die in office. Up until the turn of the last century they have been eerily accurate. The only president so far to have escaped the hex was Ronald Reagan  and even he had to dodge a real bullet to escape.

From Ring Two to The Curse of the Mummy, Sabrina the Teenage Witch to Buffy the Vampire Slayer to current horror film Cursed, American popular culture reflects an abiding fascination with the occult. Despite the flimsy overlay of postmodern jest, the voracious popularity of the genre betrays a vacuous longing for a moral order where wrongs will be punished and good will triumph over evil.

This desire to find a purpose in the workings of the universe, the recoiling against the brutal notion of nothingness, is at the heart of the religious impulse. Which is why the burghers of Carlisle would rather read a divine pattern into their run of bad luck than face up to the sheer brutality of randomness. Even if that means believing in the power of a lump of rock.

Hexes, curses, spells and fetishes could all be dismissed as so much harmless superstition. But that would be to ignore their underlying danger, which is that the mute acceptance of preordained destiny by believers bestows a license to be passive. The railings of the poor and the oppressed are just an outlet for frustration: a substitute for action and revolt. If religion is the opiate of the people then curses are someone else's used syringe.

That's why humanists have such a hard time hating. We may harbour as much malice as the devout, long just as yearningly for our enemies to develop embarrassing diseases and for their children to be barren; for train passengers who bellow into their mobile phones to be struck dumb; for motorists who enter yellow boxes without visible means of exit to be overcome by black belching smoke from their radiators; for colleagues who boast that they're on stream with their strategic objectives and making headway with clientfacing outcome initiatives to choke on their fiveyear risk assessments; for men who say they need more space to develop agoraphobia. And, especially, we'd love it if the Jehovah's Witnesses who come round on Saturday mornings would turn to pillars of stone, that Cardinal Murphy O'Connor would go into labour and then be abandoned with his own unwanted baby. Some of us would like to see Charles and Camilla squeezing their own toothpaste on the Broadwater Farm estate, while the Taliban crawl on their bellies under the rule of apostate dominatrix brothel keepers.

We may truly long for all this righteous retribution and more, but we've no magic potion to make it happen. No stones or wells, no talismans or effigies, no crystals or diamonds or charms of any kind. Like the Lollards of the Reformation and the rationalists of the Enlightenment, all we have is reason and an unswerving commitment to changing this world, since it's the only one we've got.