The Guardian’s Natalie Hanman – who edits Comment Is Free, where the party never stops – urges us to cultivate some pretentious guilt. Boldly, she asks:

Should Benedict Cumberbatch say sorry for the slave owners in his family?

Not current family members, you understand. So far as I’m aware, Mr Cumberbatch doesn’t have some weird cousin with strangers chained up in the cellar. No, we have to project our agonising backwards in time, past parents and grandparents, and great-grandparents, and great-great-grandparents – past centuries of people who are themselves strangers:

A newly appointed city commissioner in New York, Stacey Cumberbatch, told the New York Times last week that she believed British actor Benedict Cumberbatch’s fifth great-grandfather owned her ancestors on an 18th-century sugar plantation in Barbados. They “are related,” the newspaper noted, “if not by blood, then by geography and the complicated history of the slave trade.”

Which is to say, actually, not related at all.

The Cumberbatch case involves two high-profile individuals and so has had media attention, but these questions concern us all.

I suspect opinions on that point may differ.

For as long as structural inequalities persist, we cannot overlook how far the tentacles of history might reach into the present. The real challenge is to recognise, and address, how much the privileges of the past continue to benefit some, and wrong others, today.

We “cannot overlook” these things, you see; we must “address” them and weigh our privilege. Some more than others, it seems. So says the woman who gets paid to invent esoteric problems and then fret at length in print. But those “tentacles of history,” through which our “collective responsibility” is supposedly transmitted – and with it, lots of lovely, lovely guilt – reach an awfully long way, across continents, cultures and all manner of events. From the theft of sheep and chickens, and subsequent hangings, to all kinds of nepotism, tribal slaughter, imperial invasions and counter-invasions, the extinction of fluffy creatures and high seas piracy. It therefore isn’t entirely clear why an accountant’s line should be drawn so confidently at any given point, as opposed to any other given point. If the objective here is to search out some vicarious moral contamination, surely we should be thorough? If the game is genealogical guilt, why stick to mere centuries? We’ve all of history to play with. And what if a single family line includes both slaves and owners, lords and labourers, inventors of vaccines and kickers of kittens? What kind of retrospective moral arithmetic will untangle those knots?