Here's a couple of fragments from the far past which drifted back into mind as the TV news showed youngsters on the Shankill hurling petrol bombs at the police and, next item, Edwin Poots and Jeffrey Donaldson making their pitch for leadership of the DUP.

In memory's eye, I'm standing at the doorstep of a house in the Fountain, a Protestant working-class area in Derry, which, murals apart, was indistinguishable from the adjacent Bogside, trying to persuade a harassed and gracious couple to abandon a life-time's allegiance to the Ulster Unionist Party and to vote instead for the Northern Ireland Labour Party - ie. at the time, me.

This was February 1969. The DUP was as yet only a rheumy glimmer in the eye of the bible-and-thunder preacher-man from Ballymena, Ian Paisley. The Ulster Unionists ruled the roost.

"It's OK for ye down there in the Bogside," I was told across the threshold. "There's Eddie McAteer or John Hume or you to vote for, but we have nobody."

Well, somebody must have voted for the unionists, I ventured. You have a unionist MP. "Him! A useless slabber! We have nobody to vote for."

That's as near word-for-word recall as I can manage. Nobody to vote for except to vote again for Commander Albert Anderson, a stuffed shirt with ribbons attached, representing the Ulster Unionist Party.

Fifty-two years on, things have changed, although, it often seems, not a lot. Party-political configurations have shifted. Back then, Commander Anderson's UUP was dominant. Now it's the DUP, wherein Mr. Poots and Mr. Donaldson wriggle and scratch as they reach for the top. At least there's two of them in it now. More than half-a-century of blood and snotters and that's what the Fountain and the Shankill have to show. Two of them.

The DUP contest is coming to a close even as we speak. As to which contender we should be rooting for along the final straight, I am minded of the Year of the Four Emperors, 69 AD, when Galba, Otho, Vitellius and Vespsian sent their soldiers out to spill one another's guts across the streets of Rome as they sought to succeed recently-murdered madman Nero. Watching the blood slurp, the historian Tactitus mordantly foretold that "Whichever of them wins will be the worst."

More generally though, the integrity of the old enmities holds on. I haven't heard any of the Shankill insurgents dub Poots or Donaldson a slabber. But it's what they mean when they speak with scorn of "the politicians." So far, however, such antipathy hasn't presaged a crumbling of the two-communities model of Northern society. Nobody else to vote for.

All bleak, then, looking back as we face the future? Not entirely.

The scariest moment of the Shankill ructions came when a crowd of young Catholics gathered to exchange petrol-bombs, firecrackers and rocks with their counterparts across the peace-wall at Lanark Way. At one point, the huge metal gate was battered open. Television pictures showed silhouette figures on both sides flitting back and forth against a background of flame and shrieked sectarian hatred.

At the beginning of February 15 years previously, the Lanark Way gate had been flung open for a meeting on the peace-line at which I was among the speakers. A strike had erupted in a postal depot near the Shankill. A manager had seized a diary from a locker during lunchtime. The entire depot walked out. Within hours, the Falls office had joined in. Then the North's main sorting centre at Mallusk. The strikers called a march, up the Shankill to Lanark Way, through the gate and down the Falls. Postal workers and supporters converged from both sides. Because I'd earlier spoken up for the strikers, I was invited to say a few words. The meeting was held on the same spot as last month's mayhem.

Twice along the march up the Shankill, people had come out from the pavement. Literally, they used the same words: "You are very welcome on the Shankill Road, Mr. McCann." I particularly remember the "Mister."

I think I can say that my few words at the peace-line went down well.

Now, try to think of any other context in which that sequence of events could have come about.

In the course of the North's hundred-year history, the only occasions when people have come together in large numbers from "hardline" areas have been occasions when they have come together for reasons which had nothing to do with the specific interests of the communities to which, so to speak, they belonged.

It's when class trumps community that sectarian division fades.

This cannot be the end of debate about how to soften the hard edges of hostility. But it could be a beginning.

Speaking at Lanark Way, I had, naturally, mentioned the contentious diary. Immediately I stepped down from the chair which had served as a platform, I was summoned, in a somewhat peremptory manner, I thought, by a group of fellows including a couple with tattoos indicating loyalist sympathies. "C'mere, we want to talk to you."

"Just marking your card, McCann. It's not a diary, it's a londondiary."

Not a bad joke. I smile at it occasionally when there seems little to smile about.