Why are manhole covers round?

The common answer is obvious once you hear it: A circle is the only shape of cover that can't accidentally be dropped into the manhole.

But there's a problem with that answer: It's not true. You can't drop a triangular cover through the hole, either.

So what is the advantage of a circle over a triangle? Even more obvious: You can roll it. Since manhole covers can weigh 150 pounds or more, the ability to roll them is advantage enough, with the added benefit that they can't fall down the hole.

But there is another shape that meets both criteria, which is our latest addition to the Ethical Lexicon:

The Reuleaux Triangle (Reu*leaux tri*an*gle/ ROO-loh TRY-ang-guhl) noun

A curved shape made by rounding out the sides of an equilateral triangle, i.e., a plump triangle with rounded edges.

If you're old enough, you'll remember when Mazda introduced its rotary automobile engine in the 1970s. The spinning rotor that replaced the gasoline piston was a Reuleaux triangle. And although Mazda eventually abandoned the design, the carmaker had good reason for hoping that its innovative model would catch on.

The shape predates the 19th-century German engineer for whom it is named, Franz Reuleaux. Gothic window makers used it in medieval architecture, as did Leonardo da Vinci for map projection. Guitar picks, fire hydrant nuts and drill bits that produce square holes all take the shape of the Reuleaux triangle.

You also find the shape at the center of Venn diagrams, incorporated into the antennae of Hawaii's radio-wave observatory on Mauna Kea and used to make pencils that are more comfortable to hold and won't roll off the table. But what does it have to do with ethics?

If you can recall those Mazda commercials, you might also remember a 1971 animated movie titled "The Point." The young hero, Oblio, finds himself banished from his kingdom for the crime of having a round, rather than a pointed head. What he learns along the way is that "you don't have to have a point to have a point."

In our polarized society, we're increasingly threatened by anyone not exactly like us, often because we can't clearly articulate the point of our own existence, even to ourselves. So we distance ourselves from anyone different, afraid of either being reminded of our own insecurities or eliciting disfavor from our own tribe for fraternizing with the enemy.

But seeking common ground does not mean surrendering our values. The Reuleaux triangle is not a compromise between a triangle and a circle; it's a hybrid, integrating the advantages of each and thereby transcending the sum of its parts.

A well-intentioned fool once approached the saintly Rabbi Israel Meir Kagan to complain about the many different customs found throughout the Jewish community. "Why can't we all observe our tradition in the same way?" he asked.

The rabbi smiled and replied: "Imagine you are the general of an army. An efficiency expert comes to you and says: 'General, look at your troops. They're a mess! You have infantry over here, cavalry over there, artillery on the hill, sailors off the coast. You need to get all your men organized and consistent.'

"You would laugh in this person's face," the rabbi continued. "An army needs different types of soldiers to operate in different types of terrain and respond to different situations. It is the differences that make any operational system stronger."

In a healthy, differentiated society, radicals on the left and reactionaries on the right find no standing. A culture of mutual respect creates a self-correcting system that disenfranchises extremists and disempowers their corrosive rhetoric.

There will always be those who exploit diversity by attacking outsiders for being too extreme and crucifying insiders for not being extreme enough. But they can only control the narrative if the rational majority remain silent.

A functional pluralistic society works to maintain — or restore — balance and harmony in words, ideas and all interpersonal exchanges. When we take from the best of the right and the best of the left, we can channel our passions in a way that builds up our world rather than seeking to tear it apart.

See more by Yonason Goldson and features by other Creators Syndicate writers and cartoonists; visit the Creators Syndicate webpage at www.creators.com.

Photo credit: Kéoma Oran at Unsplash