It took our great poet Seamus Heaney to draw out from the dreadful horror of the 1976 Kingsmill massacre the one simple action in the midst of it which he believed, even in the teeth of cruelty, provided us with the simple ambition this society needed to survive.
The massacre sits at the centre of his acceptance speech for the Nobel Prize in 1995. As the workers' van is stopped by paramilitaries, Catholics are ordered to step out onto the roadside. There is only one Catholic in the van. There is a sense that any Catholics are to be murdered now in a tit-for-tat killing. In the darkness, that one person readies himself to move when, as Heaney says, "the story goes, he felt the hand of the Protestant worker next to him take his hand and squeeze it in a signal that said no, don't move, we'll not betray you".
Of course, the worker does step out and, instead, finds that the remaining men in the van are gunned down, for these are not loyalist killers, but what Heaney describes as "members, presumably, of the Provisional IRA".
The poet reflects that, sometimes in wars, dreadful deeds are sanctioned. We can all imagine, or recall, actions which were utterly shocking and bloody, from various conflicts. But Heaney's reflection - in what he calls "a moment of exposure to interstellar cold" - is fleeting. He judges memorably that "the birth of the future we desire is surely in the contraction which that terrified Catholic felt on the roadside when another hand gripped his hand, not in the gunfire that followed, so absolute and so desolate".
This is no mere wishful thinking, or a dodging of the issue. It is not the case that the poet is opting for the weak solution in preference to the harder, "manly" insight of violent action.
In fact, there are two moments involved in the scenario he describes on that roadside. Certainly, there is the action of the hand in the darkness - to all intents and purposes an unbearable moment of compassion and courage.
But there is also the other action, which we may miss in the narrative. The man whose hand is held in that supportive clasp in fact steps away from it, in the belief that he himself will then be the only person murdered.
In that action, regardless of how the horrendous sequence of events which follows plays out, there is also an act of self-sacrifice which it is impossible to anticipate.
Had that worker been murdered, we would never have heard of the hand clasp in the dark. We would never have understood that, in the middle of what Heaney calls the "abattoir" of our history, was there such a moment of profound human empathy that it makes us stop and wonder even in the horror.
It is an act equivalent to Gordon Wilson's tremendously forgiving humanity after his daughter's murder in the Enniskillen atrocity. But, at Kingsmill, the humanity occurs in the dry, secret and silent dead centre of evil action.
Though the fact of the massacre itself would ensure it survived in our culture as a moment of horror, with many another ghastly deed, it is those secret affirmations within the horror which mean it still resonates so powerfully. Ten of the 11 lined up on the roadside were murdered. The one survivor of the actual shooting was shot 18 times.
It is against this extraordinary backdrop that Sinn Fein MP Barry McElduff posted a video of himself horsing around with a loaf of Kingsmill bread on his head on the 42nd anniversary of the massacre.
Barry McElduff's video is nasty, offensive and indefensible. Even in the most charitable light, the event required such a sequence of spectacularly crass gaffes as to be almost miraculous as an accident.
Why that brand of loaf? Why that day? What point was trying to be made in any case?
There is also within the Sinn Fein culture a certain very obvious reckless bravado when it comes to the legacy of the "armed struggle" and how its shocking excesses are to be squared with the realisation that it was counter-productive, self-defeating and itself a cause of so much of the hardcore obstacles which now bedevil the peace process which replaced it.
It's odd how the most shaming, dreadful, inhuman and blood-thirsty atrocities seem to resurface repeatedly in our culture. Jean McConville, Greysteel, Darkley, Bloodies Sunday and Friday, Loughinisland, Omagh, Shankill... These will not go away, but return even involuntarily to haunt our civic discussions.
Until there is a method or a model to begin accommodating ourselves to the horrors we committed - to begin remembering not just the innocence of the innocent, but their bravery, their goodness, their humanity - these frightening monsters will return, never giving us a moment's peace.
We have much to remember. The Goya-esque suffering of the victims of the Shankill Butchers. The bloody-faced and dazed survivors staggering away from the Abercorn bombing. The soldier separated from his unit, surrounded by hostile women but still refusing to use his rifle while gunmen were on their way to kill him. The boy killed by the Army. The sobs of a young boy as his RUC father was laid to rest. The cleaner in a police barracks blown up taking his daughter to school. The father identifying his dead son on Bloody Friday by a box of trick matches. These terrible things happened. Here. To us. By us. And there isn't a single one of those actions which any of us can reflect upon and think "that was well done".
That, dear reader, is the real reason no one has been prepared to step forward and volunteer their identities as the perpetrators of those actions which were to "free Ireland" or "defend God and Ulster".
We cannot just pretend now these things never happened, that they were some inexplicable aberrations that have nothing to do with us.
This is not a "we are all guilty" get out of jail card. We aren't. Most of the victims, most of the bystanders, were people who had never handled a gun in their life. That was the vast majority of us then, as it is the vast majority of us now. Individuals should have to answer for their actions.
But what is needed is a series of reconciliations based on something broader than guilt. It must be a refusal to forget embedded in our imaginations.
It must also be a final recognition that there can never be here again a validation of that step into "interstellar cold" and that anyone who takes that step is a criminal, a butcher, a murderer. It must mean being clear for ever that, in our little world, violence didn't work and does not work.
Until that realisation is embedded in us all, the victims of our nightmare past will keep returning.
Sadly for them, unlike Barry McElduff, their punishment for being innocent wasn't just three months' suspension from their lives.