One of the most important functions of art is to offer a voice to an essential but otherwise neglected constituency within the culture, by which I mean the dead.

The fact we continue to pay attention to paintings, sculpture, literature and music produced centuries ago is not merely a crucial element for understanding what has made us what we are, but a way in which we continue a conversation with those who have provided insights into the human condition, or striven for the sublime.

Of course, you could always save yourself the trouble of trying to understand the interests and priorities of the Egyptians, Greeks, Romans, Chinese of the T'ang dynasty, the great artisans of medieval Europe or Impressionist masters such as Cezanne and Degas by simply asking Joan McAlpine, Archie Graham and Sir Angus Grossart to second-guess their intentions. That, at any rate, is the logic which these worthies seem to have applied to the Burrell Collection.

The terms of Sir William Burrell's bequest to Glasgow, which includes outstanding examples of all the work listed above and much more, contained a strict condition that it not be lent overseas. Sir William was concerned about the risks of transporting works of art and, since his own business was shipping, we may conclude he knew what he was on about.

The trustees of Glasgow Life, members of Glasgow City Council and MSPs scrutinising a bill to amend these provisions have, however, concluded that, were he around today, Burrell would be keen for his collection to reach a wider audience. If you ask me how they reached this conclusion, which so conveniently accords with their own wishes, or whether Burrell would have approved or not, I cannot tell you. All I have to go on is the trivial detail of Sir William's express instructions on the matter, which were exactly the opposite.

That's not the only thing I find confusing about the justification for ignoring the conditions of the bequest. Part of the impetus seems to be the fact the Burrell's museum in Pollok Park will be closed for refurbishment (though why it needs £45 million worth of repairs only 30 years after it was built is another, entirely separate, question) and that touring the collection might bring in some money to pay for it. But the Holyrood committee specifically expressed its doubt about whether it would generate revenue.

Another claim is that, given the quality of the collection, it is not as well known as it should be, and that lending works from it will promote Glasgow internationally. This, too, seems a bizarre argument. Surely the best way to get people to visit the city and the museum is not to send its contents to Tokyo or Detroit or wherever, thus saving everyone the bother of having to come to Glasgow in the first place. If you want to see Rembrandt's Man in Armour or Dalí's Christ of St John of the Cross, you go to the Kelvingrove to see them.

In any case, despite the undoubted benefits of the huge temporary exhibitions which dominate the world's principal galleries, there are commensurate disadvantages. Too often they become overcrowded spectacles - the Leonardo show at London's National Gallery last year may have been magnificent, but it was also so packed it was difficult to see the pictures.

The blockbuster model may generate revenue, but it is no way to see and appreciate art; there are indications the gallery world is waking up to that fact, and deciding that staging such shows is more trouble than they are worth. It is because Glasgow is lucky enough to have a collection of the quality of the Burrell that we should be keen to encourage visitors to come to see it, rather than exporting it elsewhere.

And part of the point is that it is a collection; what the items have in common is the sensibility of Sir William. He intended for them to be seen together by the citizens of Glasgow in a rural setting, and not to be lent overseas.

Whatever the panjandrums who are now in charge think, all of those instructions were clear enough. We got a world-class collection, and £250,000 at 1944's prices to house it. It's not only ungrateful, but unconscionable, to ignore the one clear condition attached to that very generous gift.