A marathon runner after yesterday’s attack. Photo: Alex Trautwig/2013 Getty Images

It started, as it always has, with a pistol, and ended, as it never has, with a bomb. Just before three o’clock yesterday afternoon, two explosions rocked the Boston Marathon, thirteen seconds apart and a few hundred feet from the finish line. As of this writing, three people were killed, including an 8-year-old boy, and at least 140 were injured, some of them critically. For the wounded and the dead, for their family and friends, for the 23,000 participants, for the half-million spectators, for Bostonians, for runners everywhere, for all of us, it was the saddest and most horrifying chapter in the most storied marathon in America.

A few hours before the explosions, I headed out the door for my own run, up in the hills of the Hudson Valley. The day was mercifully springlike; sunlight fell on the surface of a creek, the snow that a week ago still lingered on shady north-facing stretches of trail had finally melted away, trees at the lower elevations were unfurling the first pale green leaves of the year. Two hours later, emerging from the woods and heading home, I paused to check my watch: 2:47 p.m. Two hundred miles north of me, 17,000 marathoners had already crossed the finish line. The remaining runners were strung out along the course, closing in on the homestretch or coming through Brookline or working their way — as, without knowing it, we all were — toward the brutal part near the end known as Heartbreak Hill.

Thirty minutes later — home, showered, fed — I opened my computer, curious to find out who had won. The first thing I felt was horror. The next, after a flurry of phone calls, was the dark wings of the There But for the Grace of God bird, brushing against me as it passed on by. How many timing chips have I velcroed around my ankle, how many race numbers are stashed in my upstairs drawer? And what of the beloved friend in Boston, the many acquaintances running this year’s marathon, the way my sister might so easily have taken my niece to watch the runners right there at the best part, where they cross the finish line?

But something broader than the shock of the near miss undid me yesterday. If the explosions had happened a few miles away, over in Fenway Park in the middle of a game, the media would be calling it an attack on Red Sox Nation. But what runners know — and I say this with some hesitancy, because I mistrust all forms of patriotism — is that we are a nation, too. Back in February, I found myself on an icy trail in the foothills of the Adirondacks; it was 27 degrees and sleeting sidewise, so I was startled to suddenly come across another runner, heading the opposite direction. He gave me the slightest of nods, so familiar it made me smile. It was an acknowledgement of our membership in a tacit confederacy — of the borderline masochistic and insane, sure, but also of all the other partisans of sweat and speed and motion and effort and the simple pleasure of propelling an object, yourself, through the great outdoors.

It is silly to say that I love the members of Runner Nation. In my experience, loveableness and unloveableness are evenly distributed across all populations, runners included. And yet, in my more charitable moods, I let myself believe that because running is so intensely individual, it is also, paradoxically, unusually communal: less jingoistic than team sports, more tolerant, more fundamentally humanist. Some Boston Marathoners ran toward the blast yesterday to help their fellow runners, just as some New York Marathoners turned in their numbers last year even before the race was canceled, choosing to volunteer in the Sandy relief effort instead. Of course, this is more likely evidence for the intermittent generosity of humanity than for any special wonderfulness of runners. But events like the marathon serve to showcase that fine streak in us. They are lovely, temporary citadels of the kindhearted and the hardworking, a land without borders whose sole eligibility test is whether you love to run.

Running is a straightforward act, but the symbolism around it is strangely mixed. On the one hand, it is intimately connected to danger and fear; running is the “flight” half of our fight-or-flight instinct. We run away from threats; we run to save our skin. And yet running is also an enduring metaphor for freedom. We run to freedom, and we run to demonstrate our freedom, and the fact that you will hear this message in variously corny and eloquent and exploitative versions from sources as different as Nike, Fugazi, and the Dixie Chicks makes it no less true. Ask the runners you know if they find running liberating. If they look at you blankly, I’ll eat my Asics.

This matters, I think, because the sensation of freedom is as rare as the word itself is common. It is rare for the least fortunate members of society because they are generally not very free. It is rare for the most fortunate because we are so free we fail to fully register it. In my own life, at least, the only time I consistently experience and appreciate my freedom is while running — and there, remarkably, I experience it almost daily. Part of that freedom is emotional and psychological. It is more effortful to breathe while sprinting uphill than while lounging around one’s house, obviously; and yet the feeling running gives me is that of being able to breathe more deeply. I am grateful for that, but also for something far more basic: not the freedom I get through running, but the freedom simply to run — a liberty I recognize in part because I have worked and traveled in areas of the world where it was not safe or not acceptable for me, as a woman, to do so.

You could argue that the inability to go for a run is, as they say, a First World problem. Fair enough: Between running shoes and running water, I’d choose the water. But you could also argue that the ability to put on a pair of shoes and head out the door is the purest freedom there is, the one that is coveted and lacked by refugees and the enslaved and the stateless and the excessively state-full — those who live in places where movement is patrolled, restricted, or simply forbidden. The more moderate position than either of these is that running is a decent litmus test of the freedom of an individual and a society. To be a runner, you must have the right to go out in public, the right to make your own decisions about your body, the right to choose what you wear, the right to decide how to spend your days — plus enough freedom from want to have at least a modicum of leisure time, and enough freedom from fear to go outside alone. John Muir called being in the mountains “a good, practical sort of immortality.” Running, it seems to me, is a good, practical sort of freedom.

After the obvious tragedies, what saddens me most about yesterday’s attacks is the potential loss of that kind of freedom: for the runners who were affected, for runners everywhere, for race organizers, for free public celebrations, for our culture more broadly. We don’t yet know who was behind the explosions, let alone what his motive might have been. But they were clearly designed not just to maim and kill but also to terrorize. I’ve heard a lot of well-intentioned people observe that the best response to terrorism is to refuse to be afraid. That is a political truth but a psychological near impossibility, at least for those closest to the terror. I’ve sometimes had the macabre thought that if I am ever the victim of any kind of violence, I hope to God it doesn’t happen while I’m out on a run. Of all the things one stands to lose in such a situation, I do not care to also lose the deep sense of liberty, of unfettered-ness, I get from running. But that, I fear, is exactly what many Boston marathoners lost yesterday.

Runners, myself included, routinely invoke “suffering” and “endurance.” That kind of talk has a place within sports, and I am not advocating against it. But these are the metaphors of the fortunate. Real suffering is not chosen. Real endurance involves not having any idea at all where the finish line is, or if there is one. And this is where I keep getting stuck. The fact is that running is simultaneously trivial and, for some of us, a daily freedom, a profound gift, and a metaphor for nearly all the rest of life. I’m torn between recognizing the limits of that metaphor and hoping, as a writer must, that somehow, sometimes, metaphor can help: that everyone hurt or scared or grieving after yesterday’s tragedy knows that they are champions, that every horrible uphill stretch eases off eventually, that we are all still here, lining the course, rooting for them, overwhelmed by the magnitude of what they are undertaking, awed by their ability to go on.