In 1862, Cecilia Douglas, a Glasgow widow, left a bequest of paintings to the Kelvingrove Art Gallery, among them an exquisite still life by the Dutch Old Master Willem van Aelst.

Following revelations in yesterday's Sunday Herald, however, visitors might now look at his luminous composition of cherries and fish with a more jaundiced eye. News that Mrs Douglas's fortune came from her husband's plantation in the Caribbean, where he owned hundreds of slaves, means that works of art once purchased to enhance the Douglases' social status, today hang in public like badges of shame.

Faced with this new information about the Douglas collection, a spokesperson from the Kelvingrove Museum's board said that whether these works should be taken off display or sold was for the public to decide. Her statement seems to suggest that if disgust with their provenance runs so high that people demand their removal, the museum will bow to their will. So should we ask for the Douglas bequest to be hidden, or sold?

As a statement of revulsion with an era that besmirches the nation's history, it's tempting to ignite a bonfire of cruelties, thereby proclaiming that those who condoned or profited from slavery are reviled rather than revered. Yet, no matter how murky its ownership, I could not throw van Aelst's work into the flames, or consign it to a vault where nobody would ever see it again.

The unpalatable truth is that slave owners often used their vast profits to buy magnificent works of art. This may have been done to purify their consciences or sweeten the air around them when visitors called, but as van Aelst's work, and that of countless other artists and architects show, treasures such as these are a two-edged legacy. Like roses, despite being grown on dunghills, and studded with thorns, they are undeniably lovely. They are also part of our heritage, a clue to what made Scotland the place it is today.

Even if one wanted to destroy the evidence of plantation owners' money, where would it end? To banish all reminders of a trade that made Britain immensely rich and powerful would be to start a snowball that would eventually obliterate half the landscape. In such a purge there would be no Tate Gallery in London, no All Souls College in Oxford; half the aristocracy would live in sink estates rather than splendour, while in Glasgow alone it would look as if an army of unmanned bulldozers had been set loose, with some of its finest houses, churches and streets wiped from the map. Beyond the city, meanwhile, dozens of stately homes would have to be razed. Because, as the compensation slave owners received when the trade was finally abolished shows, Scotland may have been small, but its role in the plantation economy was anything but.

I was struck recently, when visiting Lisbon's maritime museum, that a country so famously built on this trade cannot even bring itself to mention its slaves. Poring over models of boats and men-of-war from the zenith of the Portuguese slave-ships, I found not one word about them.

It would be equally disgraceful for us to airbrush Scotland's significant role in slavery, and do a grave disservice not just to its victims, but to their descendants too. Politicians can offer apologies, and historians can open our eyes to the past, but no country can ever fully atone for the crimes on which it is built. What it can do, though, is make sure that nobody forgets it.

Otherwise, to remove the evidence or mask the facts is to behave like an accessory to the crime. Sadly we cannot do anything to change the misery that lies behind Mrs Douglas's paintings. We can, however, take every opportunity to remind ourselves of this country's part in their origins. Given that much of its money came from this trade, Glasgow should perhaps take the lead in showing remorse with an annual day of remembrance. This could be held in the Merchant City where, apparently, only the likes of tobacco lairds were allowed to walk on streets specially paved to keep their shoes free of muck, even though, as everyone knew, their hands were blacker than a chimney sweep's.