We witnessed pure evil Monday at the Boston Marathon — a kind of debauched, monstrous cunning that leaves individuals numb with grief and asking: “Why?” Terrorism is a reprehensible tactic — no matter foreign or domestic — one that seeks to bring down as many bystanders as possible. Acts of cowardice like this are meant to suppress and strike fear in civilian populations.

But Americans are not an easily scared or subdued people. In fact, first responders who rushed toward the carnage on Boylston Street illustrated the strength, courage and commitment that embody not only the historic roots of the city known to many as the Cradle of Liberty, but also the resolve of the United States.

One of those first responders, Carlos Arredondo, was present at the finish line to support a runner honoring his son, Lance Cpl. Alexander S. Arredondo, who was killed in Iraq in 2004. Arredondo should serve as an inspiration; he rushed to help a man who had been seriously hurt in the attack. The image of Arredondo holding together the victim’s femoral artery went viral in the hours following the attack — the victim’s wounds are familiar to victims of terrorism from places as far away from us as Tel Aviv or Beirut. In a post-9/11 world, these images, unfortunately, have become a reality in the Western world.

“I kept talking to him. I kept saying, ‘Stay with me, stay with me,'” Arredondo said, his hands covered in blood and holding an American flag during an interview with Maine’s Portland Press Herald.

The horrendous scenes near the twin blast sites conjure imagery of the darkest days in American history, but the acts of heroism ought to be what we cling to in the coming days for inspiration. When our neighbors are attacked, we come to their aid. When savagery is calculated to tear our country apart, we come closer together. When our buildings are knocked down we rebuild them, taller.

This country should never allow itself to become accustomed to such despicable acts of violence, and we should find comfort in knowing that Americans are capable of setting aside relatively trivial differences in the wake of such atrocities and band together. It is a testament to humanity, to our civilization, that we are resilient and refuse to be terrorized.