Were the Irish ever slaves? There appear to be two competing reasons for saying that they were. On the one hand, it makes the case that the Irish have a history of oppression equal to the worst that any people on Earth have suffered and deserve some recognition of that.
It identifies us with the African Americans and what they have come through; from being herded like beasts out of their native lands, sold like cattle and denied all recognition of their humanity.
This argument is one of identification with the oppressed of the world. It says: we understand you and stand beside you, because our experience is the same.
The other argument ends at a different point. It says: we Irish were slaves and we got over it, so why don't you? It blames black Americans for the condition they are in as over-represented in the prison population, among the poor and the least educated. It acknowledges that their forebears were kidnapped and worked to death - and worse - but reckons they should have established their own equality by now.
One argument offers compassion with a presumption of understanding and identification. The other offers a kind of derision that refuses to be accountable.
And why should we be accountable? The Irish in America contributed to racism. They told Daniel O'Connell to butt out when he urged them to work to end slavery. Tens of thousands of them fought for the Confederacy and the defence of slavery.
Even today Irish republicans revere John Mitchel, who thought slavery was a good thing.
But, actually, we are not answerable for what our forebears did and can take no credit onto ourselves today for O'Connell or blame for the Irish in the Confederacy. That past is not still alive with us in the way that the history of slavery is still alive for many in the US.
For the problem is that the United States never purged itself of its wariness and contempt of black people. That guilt lives on.
Some have compared racism with sectarianism and there is something in that. Children here have been firebombed for being Catholic. Worshippers have been gunned down at prayer for being Protestant. We know about that stuff.
American universities have brought students here to study the similarities, but there is no Irish disaffection from the British state today like there was when Punch portrayed us as ape-like and dark-skinned, too.
I have read articles making the case that there were Irish slaves and articles that say there weren't and, ultimately, I conclude that I don't need to come down on one side or other because the argument is not about the past. really; it is about the present.
Frame the question a little differently. Were there Irish people who suffered the deepest pain and humiliation that it is possible to inflict on a human person? Of course there were.
Some starved in ditches in the Famine of the 1840s. Some were shanghaied into foreign armies and flogged and keel-hauled. Some were imprisoned in laundries and denied all freedom, had babies taken away from them and sold abroad.
Some suffer mental anguish they cannot account for and some live with the physical pain of past injuries from accidents and violence. There is probably no ledger in Heaven that tallies who got the worst out of life, whether as a people or as individuals. But, collectively, we Europeans - most of us - are in a good place compared to the lives of past generations.
We eat better food, live longer and we are housed in far better accommodation. And we have freedoms that our forebears found inconceivable.
My parents' generation had to endure toothache in a way that no one today needs to. Their parents' generation suffered infant mortality on a scale that must have broken most hearts, or hardened them. And still we haven't extinguished human misery.
The argument about whether the Irish suffered more or less than others in the past is not important compared to the question of how they fare now. And we are doing very well.
This is a First World country. It is in economic decline compared to the rate of growth 20 years ago, on both sides of the border.
Some people live wretched lives on account of mental or physical illness, low income, or abuse from others, but compare the life of, say, a taxi driver here with one in Delhi or Kinshasa and this country looks fine.
There is an argument that we have suffered under colonialism and still bear the scars. I have heard some claim that there is a race memory of the Famine, a native hurt that runs deep.
But, usually, when psychotherapy probes the source of underlying anguish it finds it in early life experience, not in the suffering of one's great-great-grandparents.
But, then, maybe the shadow cast over one's life by a surly parent is a legacy from a similarly surly grandparent. And, who knows, but that the habits of today might have been cultivated in our lineage a thousand years ago.
The question is not whether that is true, but what can be done about it.
And surely the answer is education and healthcare and material comfort and a civilised culture in which people are accorded dignity and opportunity.
These are all things which are available within our society and which considerable endeavour goes into defending against political forces which would deplete them to the level they are at in, for instance, India or the United States.
Pain inherited from the past today in Northern Ireland is more likely to be a legacy of the Troubles period, but there are probably effects still being felt in families from the horrors of the Second World War and the Great Depression.
Some have used the word Holocaust to describe the Famine in order to imply that commonality of experience between those who starved in Belsen and those who died trying to claw a decent spud out of a blighted land.
But what really matters is the extent to which the pain and injustice linger still. We can oppose racism without bearing the guilt for how our forebears compounded it and also without seeking to assert that we suffered it, too. Much of that is an unseemly pitch for sympathy that is properly due to others.
We are privileged to be more free than others, though, and we should know it. It is how we shape the world we live in now that matters.