It began with a letter. In 1517, Martin LutherA 16th Century German priest known for his role in the Protestant Reformation and as the namesake of Lutheranism. wrote to his archbishop. Why was the Church selling seats in heaven to pay for a new cathedral in Rome? The question cut to the bone of 16th-Century society and religion. It split Europe and sparked the Reformation.

Five hundred years later, some pundits think we are on the eve of another great upheaval. "The word integritySomeone with integrity is honest and has strong moral principles. is now on every political lip," writes the columnist George Pitcher. Conservative MPs say Boris Johnson is a "vacuum of integrity" and Number 10 a "lie machine". Fifty-nine MPs resigned, calling time on Johnson.

The contenders to replace him say they will restore trust and put integrity at the heart of public life. Pitcher believes something big is afoot: "Business and political leaders have for too long worshipped at the altars of selfhood and individualismThe political philosophy that values the rights of the individual over society. It is a key idea in liberal democracies and modern capitalism.." We must develop modern virtues of discernmentThe ability to judge well and make good decisions., fairness, courage and self-discipline.

Trust in politicians is in free fall. The bitter civil war engulfing the Conservatives looks set to deepen as the party braces for what is likely to become the dirtiest leadership campaign in history.

So bitter is the fight that at least two rival leadership campaign teams have passed the Labour Party a digital dossier containing a series of lurid allegations about their potential opponents.

Last year, 63% of people in the UK said MPs were in it "for themselves", up from 48% in 2014. Social scientists say this is a global trend. Across the world, "we have stopped trusting elites", writes sociologist William Davies, and "it's too late to turn back the clock".

Not everyone thinks so. Society "longs now to be led on a flight-to-integrity", argues Pitcher. A modern reformation can sweep away cronyismAwarding jobs and privileges to friends and supporters. and corruption and vote in leaders with higher and nobler standards.

Integrity politicians may want to study AristotleA student of Plato, tutor to Alexander the Great and the father of political philosophy.. The ancient Greek philosopher believed we should pursue a good life based on four cardinal virtuesCardinal means fundamental or most important. For Aristotle, these virtues were prudence, justice, fortitude and temperance.. Early Christian philosophers like Thomas AquinasOne of the most important medieval thinkers. The Italian priest called Aristotle "the Philosopher" and worked to unite pagan Greek philosophy with Christian principles. worked these ideas into the fabric of European culture.

Pitcher says the Enlightenment swapped these values for a "cult of self", defined by individualism and the pursuit of power at any cost. Society has been governed by populistsPopulism is a political approach whereby a politician tries to appeal to ordinary people who feel that they have been let down by elite groups. who say anything to get elected and a prime minister who wanted to be "World KingThe young Boris Johnson's dream job.".

Critics say we have been here before. In 1997, Tony Blair won a landslide victory with a promise to be "whiter than white, purer than pure". Leaders may use the language of virtuous public service. But they are always motivated by self-interest.

In Why Trust Matters, the economist Benjamin Ho calls trust the "glue that holds civilisation together". Everything we do depends on it. The problem, writes William Davies, is that "trust relies on a leap of faith". Distrust grows with "ever-mounting piles of evidence".

Political scientist David Rothkopf calls this an infodemicMerging the words information and pandemic. The United Nations and World Health Organisation use this term to refer to fake news and misinformation about Covid-19.: a virus of "fear, speculation and rumour" shared on social media. Too much information and misinformation make it impossible to trust anyone.

Five centuries ago, Martin Luther did not trust the Catholic Church. He argued everyone should read the Bible and make up their minds about religion. Like the Internet, the printing press helped spread this idea across Europe.

Will digital society be ruled by trust and integrity? Or by suspicion and lies? The future of democracy may be at stake.

Yes: We are tired of liars, corruption and self-interested politicians. Society cannot survive without trust. So we need a new politics of integrity that inspires everyone to believe in each other.

No: Nothing has changed. Leaders will always say what they think we want to hear. The only difference is that some politicians are more convincing than others.

Or... Change takes time. Aristotle's ideas, Martin Luther's Reformation and the Enlightenment all changed society over centuries. We should not expect miracles, but we can hope for progress.