There are many good reasons to cancel school. Snow. A hurricane. No heat. A busted water pipe.

But until last week, I had never heard of canceling schools because of what they were teaching.

I have now.

An entire school system in Virginia was shut down Friday — 10,000 students, all kept at home — after a teacher gave an Arabic calligraphy assignment. The assignment, to copy a line as written, was from a standard textbook in a standard class, world geography, with the subject being world religions.

Unfortunately, the line used was the Muslim statement of faith, which translates to “There is no god but Allah and Muhammad is the messenger of Allah.”

The kids were asked to try writing it.

They went home and told their parents.

Look out.

Emails flew. Phones rang off the hook. Anger simmered and boiled over. The textbook identified the shahada as the Islamic statement of faith, but according to reports, it was never translated to the students, nor was it taught as dogma. It was basically an art project, to see how difficult calligraphy is to reproduce. Chances are most kids had no idea what they were scribbling.

Nonetheless, parents said their kids were being brainwashed. Some called for the teacher’s firing. (Don’t they always call for a teacher’s firing?) Some, the local sheriff told the media, wanted the teacher’s head “on a stake.”

With all the angry smoke rising, law enforcement suggested — and the school board agreed — that every single school in the county be closed Friday.

And all learning screeched to a halt.

Now, there are several legitimate questions in this story. First, is there no other example of Arabic calligraphy? Didn’t anyone involved — teacher, principal, textbook editor — realize a statement of faith is too volatile for a glorified penmanship lesson?

But having asked those questions, here’s another: Do we really need to shut an entire school district over this? Have we so quickly paralyzed ourselves with fear? Are we that spooked by the mere letters of the Muslim faith? And who were the police most concerned about — Muslims, or those who hate them?

“I will not have my children sit under a woman who indoctrinates them with the Islam religion,” a mother told a Virginia TV station.

I understand the anger. It was a foolish exercise. But I’m pretty sure the teacher, whose name is Cheryl LaPorte, was trying less to indoctrinate than to accelerate, hoping to work her way through the Standards of Learning tests that are required by her job.

Now that the district has removed that sentence from the class, she can use a different line to teach the calligraphy lesson. Problem solved.

But not over.

There is a reason book burning is so unnerving. So is shutting a school. Fear stymies education. It paralyzes the mind.

Ironically, the limiting of education — and the exclusion of girls from learning at all — is a key criticism we level against fundamentalist religions — including Islam. We’ve never minded doing Christmas shows in public schools that feature Jewish, Hindu or Muslim students.

Yet here we are, closing down an entire school system — with no actual threats being made — because of a copied Arabic sentence?

I imagine the most hysterical parents would prefer their kids never learn anything about the Muslim faith, never hear the word “Allah,” perhaps never be made aware that 1.6 billion people in the world — nearly 25 percent of the global population — practice that religion.

But ignoring Islam is a clear path toward demonizing it. And if you think that’s how you win a war on terror, think again: Polarizing faiths is the surest way to make certain they attack each other.

The Islamic State would like nothing better than if we made every Muslim feel unwelcome here. People go where they feel wanted. If we remove the freedom of religion principles that make this country great, we might as well set up an express train between the U.S. and Islamic fundamentalists.

There will always be problems. There will always be issues. And, by the way, terror attacks were not invented this year, this decade or even this century.

But learning — open learning — is essential to a free society. It is the bread of a peaceful culture.

Knowledge is power. Ignorance sparks fear. Shutting down schools just means the latter is winning.

(C) 2015 BY THE DETROIT FREE PRESS DISTRIBUTED BY TRIBUNE CONTENT AGENCY, LLC.

Photo: Ahmed Bin-Baz via Flickr