What’s in a statue? The long-running debate over statues of Confederate generals in the American South has been given a larger platform because of the killing of a woman in Charlottesville. As is almost always the case in Britain, an American debate has taken on a British flavour, with Afua Hirsch, writing a piece for the Guardian saying that Horatio Nelson, the British admiral who won the decisive battle of Trafalgar against the French and Spanish fleets, should have his statue taken down due to his support for the slave trade.

First, a simple truth: public space is limited. There are only so many statues in a park. To celebrate one person you may need to store a statue of another in a vault somewhere. This problem is on stark display in parliament: a number of politicians of third-tier quality have marble statues, because their careers were over when the building was constructed. A series of impressive politicians whose achievements happened after parliament was built don’t have so much as a plaque. There is a statue of Lucius Cary, a Liberal politician of justified obscurity, but not one for William Wilberforce, who ended the slave trade, or Ernest Bevin, who helped create Nato.

So there is the case for the discreet pruning of statues in Britain, and one might as well start with the obscure or the morally dubious.

But as is often the case, that the United States and the United Kingdom share a language obscures the fact that they don’t really share a culture. (A striking but recent example: a majority of Americans believe that a man and a woman who are married, but not to one another, should not dine alone, while a majority of Europeans, including Brits, disagree.)

The problem with statues in the United States is not about the likes of Cary, whose significance, such as it ever was, has been lost to time, but because the past isn’t really past.

Objecting to Nelson’s statue because of his historical support for the slave trade feels like a category error – because his statue is not a result of his political beliefs but his success in war. To the extent that anyone thinks about the man Horatio Nelson when they pass Trafalgar Square, they think of him as “some kind of soldier”.

The Confederacy’s generals weren’t given statues because of their success in war – but in support of their pro-slavery and white supremacist views. Their statues were erected in support of those values and to assert white American primacy against black Americans. The context is wholly different.

In Britain, the number of statues with a similar history is far, far smaller. One example is that of William Gladstone outside St Mary’s Church in Bow. Gladstone’s statue was put up as a tribute by the owner of the local match factory, Theodore Bryant – and he paid for it by docking the wages of the lowly-paid matchmakers, girls as young as 13 who suffered phosphorous poisoning while Bryant himself grew rich on his company’s large dividends. To make matters worse, the statue was in part, a token of Bryant’s gratitude at successive Liberal governments’ willingness not to regulate the factory.

There is a much stronger case that Gladstone’s statue in Bow is inextricably linked with values that we no longer share than Nelson’s. If we want to get rid of one, that should surely be high up the list.