It was an uncanny serendipity. Just before we entered the library at Trinity College, Dublin, we had heard the news that Ireland's great poet Seamus Heaney had died. And, now, here we were in the antechamber to the Book of Kells, reading three quatrains of an 11th-century poem that could have been written that very hour about his death:

My hand is weary with writing,
My sharp quill is not steady,
My slender-beaked pen juts forth
A black draught of shining dark-blue ink. 

The words, entitled "St Colum Cill the Scribe", were a reminder of the toll that the shaping of words takes. Great poets do more than speak for themselves; they throat a voice which speaks for many. Heaney was, as Fintan O'Toole said the next day in the Irish Times, "not merely a central figure in the literary life of Ireland, but in its emotional life, in its dream life, in its real life". That role went beyond Ireland. It crossed the English-speaking world.

Perhaps that was why the death of Heaney felt to so many, even those who had never met him, like a personal bereavement. Roy Foster compared the news to the sensation of a great tree having fallen: "that sense of empty space, desolation, uprooting". But it was more than that.

A stream of the wisdom of blessed God
Springs from my fair-brown shapely hand:
On the page it squirts its draught
Of ink of the green-skinned holly. 

Heaney's poetry sprang, like a vigorous plant between paving stones, from the gaps between the ordinary and the mysterious, the secular and the sacred; between history and myth. It was rooted in thickly textured soil, but it pierced the veil of heaven.

It was a poetry that reconciled contradictions. He wrote of his rural past, but about our globalised present. He was a sturdy Irish nationalist who created in English. He was an Ulsterman who lived in Leinster, a northerner who settled in the south, who had a group of Catholic and Protestant clergymen walk together into the church for his funeral, as the uilleann pipes of the whole island lamented.

Heaney famously spoke of "the redress of poetry", which he explained as "the need for poets to align themselves with those who have been wronged, to repair and compensate for injustices suffered". But his profound regard for humanity, his fellow Derryman, the late John Hume, said, "made his poetry a special channel for repudiating violence, injustice, and prejudice, and urging us all to the better side of our human nature".

Heaney became the prisoner of neither side in his nation's Troubles. By writing only for himself, he wrote for us all. Diversity was part of God's ordinance. Two buckets were easier carried than one, he said.

There was a price to pay. After his stroke in 2006, he had cut down his public engagements. But this year, he was out and about again, reading, signing books, talking to his readers, blessing occasions with his presence. Yeats was a haughty poet with a large sense of his own superiority, but Heaney was a common man who understood our shared humanity.

My little dripping pen travels
Across the plain of shining books,
Without ceasing for the wealth of the great - Whence my hand is weary with writing. 

He has done the state some service, this great shaper of words. But the good went deeper and wider. "He did no one harm," said our taxi-driver; he could think of no greater compliment. Beyond silence, Seamus Heaney will still be listened for.

Paul Vallely is Visiting Professor in Public Ethics and Media at the University of Chester.