Let’s name a playground or a school after that 8-year-old boy, Martin Richard, who was standing by the finish line with his family when the bomb went off, killing him and critically injuring his mother and sister. Let’s donate to the favorite life-giving charities of the other victims. Let’s pitch in to help the injured recover. But on lovely Boylston Street in Boston, a place normally so full of life, let there be no reminder whatsoever of what President Obama called this “heinous and cowardly act” of terror.

Image Thomas L. Friedman Credit... Josh Haner/The New York Times

And while we are at it, let’s schedule another Boston Marathon as soon as possible. Cave dwelling is for terrorists. Americans? We run in the open on our streets — men and women, young and old, new immigrants and foreigners, in shorts not armor, with abandon and never fear, eyes always on the prize, never on all those “suspicious” bundles on the curb. In today’s world, sometimes we pay for that quintessentially American naïveté, but the benefits — living in an open society — always outweigh the costs.

Terrorists know that, of course, and feed on it. The explosives were reportedly packed into six-liter pressure cookers, tucked into black duffel bags and then left on the ground. That is the signature of modern terrorism: to turn routine items from our lives into bombs: the shoe, the backpack, the car, the airplane, the cellphone, the laptop, the garage door opener, fertilizer, the printer, the pressure cooker — so that everything and everyone becomes a source of suspicion.

This can pose a much greater threat to our open society than the Soviet Red Army ever did — if we let it — because this kind of terrorism attacks the essential thing that keeps an open society open: trust. Trust is built into every aspect, every building, every interaction and every marathon in our open society. Terrorists can steal it for a moment or even a while, but we dare not let them fundamentally erode it, and I don’t think we will. When you watch the video of the bombing aftermath, notice how many people you see running toward the blast within seconds to help, even though more bombs easily could have been set to explode there.

Fortunately, we don’t frighten easily anymore. You could feel it in the country on Tuesday morning. We’ve been through 9/11. We probably overreacted then, but never again. We tracked down Osama bin Laden with police and intelligence work, and we’ll do the same in this case. But meanwhile, even in this age of terrorism, let’s keep heeding the advice of an advertisement that you could see hanging in a Boylston Street window in a picture taken after the blast. The picture showed a marathoner sifting through unclaimed runners’ bags left behind after the explosion. Behind him, in the window, the ad poster says: “Your home should be a place to rest easy.”