Does anybody remember crop circles? They were these supposedly mysterious designs in crop fields that “could not possibly” have been made by humans, because they were too precise, too intricate, and too perfect. Authors wrote books swearing they were of extraterrestrial origin. Crop circle tourism became a thing, so that people could fly all over the world and experience their exotic, alien cosmic energy.

There was just one problem. They were all made by humans named Doug Bower and Dave Chorley. Every single one, using ordinary technology in particularly clever ways. They’ve since inspired other crop circle artists. Crop circles designed by aliens were a big deal when I was young. Nowadays, nobody remembers how many people believed they were evidence of alien visitation. But I do.

How about Bigfoot? For years, starting shortly before I was born, people believed in a giant gorillalike creature that lived in deep forests or the mountains, leaving large footprints behind. Others claim to have caught the elusive creature on film. For years, throughout the 1970s and ’80s, Bigfoot was a thing.

That is, until the family of the original Bigfoot “discoverer” confessed their father had been making artificial tracks with carved wooden feet kept in his garage. And as far as the “famous” Bigfoot film that made the rounds when I was growing up, investigators eventually found the costume maker that sold the gorilla suit to the actor who appeared in it.

Nowadays, nobody remembers how many people took Bigfoot seriously. But I do.

In early 2004, Mel Gibson released “The Passion of the Christ.” I went to hear a presentation by a local resident who was somehow involved with the film. I remember how he gushed with starstruck awe about what it was like to be on the set with Gibson, who “didn’t have a single antisemitic bone in his body.”

Two years later, Gibson was arrested for drunken driving. According to the arrest report, he shouted “Jews are responsible for all the wars in the world!” It’s my understanding he made some sort of apology. He might hope nobody remembers that. But I do.

Why is it important to remember all the goofy things people used to believe back in the day? Because today people still believe things for all sorts of reasons that have nothing to do with evidence. When that happens, it can lead to more than just exploitation of the gullible and naive. It can fan the flames of hatred, turmoil, chaos and death.

For example, it is clear that millions of people once believed, and perhaps still do, that the 2020 election was stolen. That would imply the current president (whom I did not vote for) was wrongfully elected. The evidence says this claim is overwhelmingly likely to be false.

Members of the losing candidate’s party have been particularly eloquent in testifying how this mistaken belief led hundreds of armed individuals to storm the Capitol, with the open and enthusiastic support of the incumbent, to oppose the peaceful change of power that is an essential component of democratic (lower case ‘d’) civilization.

Or consider this. Across the ocean, hundreds of people every day are dying in a brutal, senseless war. The dictator who started it has managed to convince millions of people they are on a sacred mission to rid the world of fascism and Nazism.

The best evidence we have is that this belief is false.

Unfortunately, the evidence also shows huge numbers of his followers believe the people they are killing are not human. They believe it is good and right to slaughter noncombatants, hospital patients, children and infants, because they are evil Nazis who deserve killing. Once again, the best evidence we have says that is not true.

In the future, when we see all these views for the nonsense they were, will we remember how many people took them seriously, and what the tragic consequences were? We have to. We must. Without that memory, we risk becoming complacent. We risk losing sight of a fundamental truth of human nature attributed to the great humanitarian Voltaire, one that I have quoted before:

“Those who can make you believe absurdities, can make you commit atrocities.”