In World War I, the British and French shot hundreds of soldiers for cowardice after they deserted. Only years later was it was recognized that many of those soldiers were suffering from what we now call PTSD. Their problem was psychological, not moral.

A lot of our ideas about cowardice come from our ideas about war. In war, the willingness to kill is considered a virtue. So is the willingness to die. Refusing to live up to those standards is dishonorable.

When Nikolas Cruz walked into Marjory Stoneman Douglas High School with a semi-automatic rifle one recent afternoon and started firing, Scot Peterson, a sheriff’s deputy stationed at the school, would have charged after him, drawn his own weapon and brought Cruz down.

Or better yet, would have talked him down.

However it happened, in that better world at least some of the 17 students and teachers killed in Parkland, Fla., would still be alive.

Several headlines have said Trump flat-out called Peterson a coward.

But “coward” is a word Trump likes.

Calling someone a coward is one of the worst possible insults.

A coward is the opposite of a hero. Cowardice is the antonym of courage.

A hero confronts the attacker head-on, runs into the burning building to save the baby, speaks truth to power regardless of the peril. The coward cowers.

Cowards are not merely weak; they’re deemed shameful. They have not only failed, their failing is deemed immoral, contemptible, damnable.

We toss the word at others like a poison dart, rarely turning it on ourselves.

But how many of us can be sure of our own courage? Most of us never have it tested in dramatic, public, physically dangerous ways. We can only know what we hope we’d do, the sacrifice we hope we’d make, when the bullets or the fire or the interrogation squad came.

“Cowardice, as distinguished from panic,” Ernest Hemingway once wrote, “is almost always simply a lack of ability to suspend the functioning of the imagination.”

I’m not entirely sure what that sentence means, but the distinction between cowardice and panic is important.

The word “cowardice” implies a choice, a selfish decision made out of fear and with disregard for others. Panic, as one dictionary puts it, is “sudden uncontrollable fear or anxiety, often causing wildly unthinking behavior.”

The key word there is “uncontrollable.”

Some of what we call cowardice is beyond choice. It’s a self-preserving reflex of the brain and body, nothing at all to do with morality. Some people are better constituted than others to metabolize fear.

Sometimes what we call heroism is just adrenaline in action too, as much a physical response as a moral one.

Who knows what Scot Peterson was thinking as he stood outside that high school while a rifle went off repeatedly inside? He may have made a conscious, selfish choice, or he may have panicked. We can wish that people trained to serve and protect wouldn’t panic, but they’re human, and it is only human to protect our own lives.

And who knows whether his intervention would have saved anyone?

The Parkland shooting shows us, once again, that the threat from disturbed people with easy access to guns is real. We’d be smart to worry less about the so-called cowardice of one deputy and more about the cowardice of politicians afraid to pass the laws and funding to address the mental health issues this country is facing.

Scot Peterson will spend the rest of his life wearing his badge of shame.

As a country, we need to face and start to confront the issues of mental health, including an educational system which is dealing in a poor way with the mental health of their students.