Ronald Reagan was wrong. The nine most terrifying words in the English language are not “I’m from the government, and I’m here to help.” They are: “The arc of the moral universe bends towards justice.”

It’s a pretty phrase invented by a good person, Theodore Parker, and revived by another good one, Martin Luther King Jr. But it’s terrifying because it evokes unjustified confidence that history is on your side. This has consequences. Donald Trump might not be in the White House if progressives hadn’t been so convinced that the moral universe was bending their way.

The phrase presumes history has a predetermined direction. But Karl Popper demonstrated such historical determinism is based on a fallacy: The arc of history is shaped by inventions, and we cannot predict what these will be.

Every day brings more evidence this vision of history is wrong. In the 1990s, liberals predicted that, thanks to the “moral arc,” democratic capitalism would triumph globally. Great sociologists such as Max Weber and Emile Durkheim predicted modernity would bring bureaucratization and secularization.

But the first defining act of the 21st century was the destruction of the World Trade Center by 19 religious fanatics. Now democracy is in retreat, strongmen are on the rise and Trump is dismantling the rules-based global order. These leaders are recreating patrimonial regimes in which governments are like royal courts and the state is treated as family property. This is much more Vladimir Putin’s world.

Economic productivity has improved since the mid-18th century, but the idea this produces moral or aesthetic progress is nonsense. Hitler took power in Europe's best educated, most culturally sophisticated country. Progress in one area often brings regress in another.

The illusion of history begetting justice is terrifying for two reasons. First, it encourages an often counterproductive false sense of confidence. Democrats’ confidence that history was on their side led them to underestimate Trump so badly they stuck with Joe Biden even though it was obvious his powers were fading. This confidence also led the party to endorse unpopular causes, which could be lumped together as “wokery,” on the grounds that they were akin to the civil rights movement. To hell with the people who question these causes even if they happen to be the majority.

Before that, that confidence persuaded the U.S. establishment to embrace China with open arms, subcontracting much of America’s manufacturing to the country, even though the Leninists who ran the regime were determined to replace the U.S. as the world’s leading military and industrial power.

The second reason it’s terrifying is it encourages people to subcontract their moral judgments to history. Most progressives did not treat the problem of transgender people’s rights as a nuanced moral issue involving careful balancing of the rights of biological women and trans women, or a careful consideration of the potential harms of powerful drugs and invasive surgery. They rushed to be on “the right side of history.” The notion of the moral arc encourages groupthink and the blindness and bullying that comes with it.

It is healthier to treat history as an open-ended process made by individuals who have to wrestle with their own moral judgments. “History is all things to all men,” as Herbert Butterfield put it. “She is in the service of good causes and bad.”

Progress is something made rather than predetermined — and thinking you are on the winner’s side too early can put you at a disadvantage.

The last group of “progressives” who thought they knew the direction of history were the Marxists who preached the inevitable triumph of Communism even as Communism was collapsing. The danger is that today’s progressives will preach the triumph of progressivism even as strongmen dig themselves deeper into power across the world. Events only move in your direction if you put in the work to steer them that way.

Adrian Wooldridge is a global business columnist.