Growing public protests against the re-imposition of the Government’s chaotic, confusing and contradictory lockdown rules have drawn a curious coalition of supporters: ranging from rational and moderate objectors to professional conspiracy theorists such as the “lizard king” David Icke, and Piers Corbyn.

The same tropes which characterised anti-Jewish attacks are a feature of modern conspiracy theories

We have been here before. Throughout history, the devastating plagues that have swept the world have been followed in their wake by eschatological movements preaching irrational doctrines of imminent catastrophe, often tinged with religious fanaticism. The mid-fourteenth-century Black Death for example, which killed between a quarter and half of Europe’s total population, was followed for centuries by returns of the bubonic plague, closely accompanied by such phenomena as the “witch craze” persecutions, flagellant sects and antisemitic pogroms.

The most recent global pandemic in terms lethal virulence was the 1918/19 Spanish Flu, which wiped out an estimated 50 million victims. Coming hard on the heels of the Great War, which itself had incurred the deaths of up to 10 million soldiers and civilians alike, it is unsurprising that the following decades were characterised by symptoms of popular derangement, including the rise of fascism and communism, renewed attacks on the Jews, and Europe-wide political and economic instability culminating in the Second World War.

Historians have seen such flights from reason as a reaction to worlds turned upside down by terrifying and seemingly inexplicable events. If the props of normal life are suddenly removed, and the old order is abruptly overturned, people grasp blindly for explanations – and for scapegoats to blame, however absurd they may be. In G.K. Chesterton’s words, “When men choose not to believe in God, they do not thereafter believe in nothing. They become capable of believing in anything”.

Battered by Covid-19, lacking competent leadership, threatened by hostile and aggressive forces abroad and shaken by massive technological change at home, the question arises: is the world due to undergo another flight from reason? A glance at the conspiracy theories currently doing the rounds suggests that reason is indeed retreating, and the descent into irrationality may be closer than we would like to believe.

I recently met a new acquaintance who, to all intents and purposes appeared “normal” and held a responsible position in the NHS, solemnly assured me that the world was run by a wealthy criminal elite addicted to a powerful drug extracted from the blood of murdered children.

This appears to be a version of the QAnon conspiracy theory which has been gaining traction in the US, but is also – worryingly – attracting adherents here in Britain. Broadly, believers in QAnon claim that a secret Satanic paedophile cult rules the world via control of the media, entertainment, and political parties. The only barrier to this cult gaining complete global hegemony, goes the theory, is the unlikely figure of Donald Trump, who is aware of their fiendish plans and is battling to overcome them.

Variations on this theme of secretive cults controlling us like puppets include anti-vaxxers who claim that Microsoft boss Bill Gates is planning to insert a microchip along with the anti-Covid vaccine if and when it is developed – the better to monitor and manipulate us – and the 5G conspiracists who link the rollout of 5G technology with the global spread of coronavirus, and have even destroyed 5G masts in their quest to prevent it.

While it is true that the advent of the internet and social media have facilitated the spread of such wacky theories, such conspiracies themselves are nothing new. The idea of an all-powerful secret elite who are either already running the world or are plotting to do so is a very old one, with rancid roots deeply entrenched in European history. Groups targeted in the past accused of fomenting such plots include the Jesuits, the Illuminati, the Freemasons and – most persistently and destructively – the Jews.

Conspiracies may begin in the realms of the ridiculous, but too often they end in a river of blood

Interestingly, the same tropes which characterised historical anti-Jewish attacks and sentiment are also a feature of modern conspiracy theories. The notion that children are kidnapped so that their blood may be extracted to provide a drug for the elite echoes the age-old anti-Semitic “blood libel” conspiracy: the myth that Jews abducted and murdered Christian children in order to use their blood for baking Passover bread. The theory that an elite conclave meets in secret to plan their takeover of the world is a reprise of that hoary old forgery, The Protocols of the Elders of Zion.

Traditionally, the British have prided themselves on their pragmatism and have remained remarkably immune to the plots, pogroms and paranoia that have so frequently disgraced and disfigured our European neighbours. Nevertheless, it is important not to forget that we have also perpetuated such historical prejudice: in 1190 the entire Jewish community of York, some 150 people, committed suicide rather than be murdered or forcibly baptised by a raging mob. A century later, King Edward I expelled all Jews from England, and they were only readmitted by Oliver Cromwell in the 1650s.

Twenty years after that, scores of innocent Roman Catholics were judicially murdered in the “Popish Plot” purely on the say-so of Titus Oates, a deranged ex-clergyman who accused them of plotting to kill all good Protestants in their beds. Conspiracy theories may begin in the realms of the ridiculous, but all too often they end in a river of blood.