Barbarity repeatedly produces chilling reminders of man’s inhumanity to man. But for a manifestation of utter brutality run amok, a mass-murder shooting spree at an elementary school is about as harrowing as it gets.

Friday’s stunning news of that horrific act at Sandy Hook Elementary School in Newtown, Conn., delivered an awful jolt that thundered across and beyond America.

According to the authorities, a lone, 20-year-old gunman killed 26 people at the school. Twenty of the fatalities were children. Then that killer killed himself.

The police also said that he killed his mother — a Sandy Brook kindergarten teacher — at her home before launching his attack at the school.

By now, the grotesque spectacle of twisted monsters in human form using dreadfully efficient firearms to inflict wholesale carnage has become all too familiar. For instance, on Tuesday, another shooter reprised that sickening scenario at a mall in Portland, Ore.

Three people died in that incident. Again, one of them was the killer, who turned one of his weapons on himself.

In the staggering wake of Friday’s outrage, President Barack Obama aptly expressed our nation’s “overwhelming grief.”

Wiping away tears, the president deplored the “heinous crime,” adding: “The majority of those who died today were children — beautiful, little kids between the ages of 5 and 10 years old. They had their entire lives ahead of them — birthdays, graduations, weddings, kids of their own. Among the fallen were also teachers, men and women who devoted their lives to helping our children fulfill their dreams.”

However, the more than two dozen lives lost weren’t the only casualties. Such mind-numbing, senseless violence inflicts widespread shock and despair.

Yet this appalling assault on that quintessential symbol of innocence — children — must prompt renewed debate about how to minimize the risk of such savagery.

And regardless of what laws we pass and/or enforce, there’s no minimizing this ugly, enduring truth:

Just as our species has an inspiring capacity for good, it has an insidious capacity for evil.