Later this month the Treasury must decide whether to support the campaign to save Titian's great masterpiece, Diana and Actaeon, for the nation. The National Galleries in Edinburgh and London must raise £50 million before the end of the year, or else the painting will be sold on the open market, at which point it could fetch at least double that amount for its owner, the Duke of Sutherland.

Arguing the case for public money to be used in securing yet another 16th-century Italian painting might seem a tough challenge at the best of times. In the midst of international financial turmoil, it bears the hallmarks of a lost cause. Across the country jobs are being squeezed, families are facing hardship, companies are going to the wall. The Government is already committed to a bailout for the banks which has exposed the country to a massive level of debt. In these conditions its first duty must be to the welfare of taxpayers. There is no spare money around.

This is not just another painting. As artists of the stature of Lucian Freud and David Hockney have argued with passion, this is an icon of the Renaissance, possibly the greatest painting of one of the greatest masters of his time. Along with its sister work, Diana and Callisto, it has been in Britain for more than two centuries.

These paintings are not merely relics of the past. They have given pleasure to generations of visitors, provided a stimulus to students and academics, acted as an inspiration to contemporary artists from Howard Hodgkin to Damien Hirst. They are, in short, a vital part of Britain's contemporary reputation as the home of great art. When Freud, a man not given to public utterances, describes the works as “simply the most beautiful paintings in the world”, then we should stop and think seriously about what is at risk.

A nation is judged, not just by its ability to manage an economy or attend to the welfare of its people, but by the importance it attaches to its cultural heritage. The richness of Britain's collections and the vigour of its artistic tradition are part of our contribution to the civilised world, and successive governments who inherit that tradition have a duty to nurture it. The fact that the campaign to save these works of art has coincided with an international crisis should not detract from their significance - indeed it throws them into sharper focus. Set against the shaky values and fluctuating performance of our financial institutions, great art reminds us of something more permanent and lasting - the human ideal, the aspiration of fine minds, the quest for beauty.

This is not a government that has paid great attention to culture or displayed much interest in the role that it plays in the character of the nation. It is happy to claim credit for achievements on the stage or the sporting arena, but is less enthusiastic in promoting a cultural debate. But it may care to note that the campaign to save the Titians has aroused interest across the world, and has inspired not just most of Britain's leading artists, but members of the public as well to champion the cause. It is therefore a popular issue and not just an aesthetic one. Supporting the effort to keep these great works in the country may well arouse controversy, but it is the right thing to do, and future generations will be grateful for it. In troubled times, an attachment to great art is the mark of a civilised nation.

The Impressionist Pierre-Auguste Renoir once wrote that a work of great art should “seize upon you, wrap you up in itself and carry you away”. It is “the means by which the artist conveys his passion. It is the current which he puts forth, which sweeps you along in his passion.” He added: “The pain passes, the beauty remains.” It is a motto that deserves space on the walls of the Treasury.

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