Simulacrum:

a good word to conjure with on a Saturday morning. It means the "image or representation of someone or something". It has also come to mean something that is an unsatisfactory imitation or replacement for the real thing.

It was a word that came to mind when talking to David Mullane this week. Mr Mullane is a former director of the Charles Rennie Mackintosh Society and is chairman of the Friends of the Glasgow School of Art (GSA). Simply put, he does not want the GSA to rebuild the Mackintosh Library, which was destroyed by the disastrous fire in May.

Speaking in a personal capacity - not as the voice of the Friends - he said the library was a work of art. Works of art can be damaged and repaired, but once they are destroyed, they cannot be replicated and remain the same work of art. If it is remade, it would not be the same library - of course. It would, in his view, be in danger of merely being an imitation of the original, a prime example of "Mockintosh" as well as an "embarrassment". Mr Mullane says it is far better to start again - not try and create a simulacrum of something made and then lost in the past, but commission something new and bold to fill the same space in the wounded building.

One could have sympathy for this view. The library is indeed gone, and recreating it - while perhaps best for tourism, the Mackintosh industry and heritage bodies - does risk turning the GSA which after all is still primarily a place of work for students and tutors (is it not?), into a museum. And the library, from this view, would not be "real" anyway. It would be a facsimile. Like the streets in the Riverside Museum, or the Eiffel Tower in Las Vegas. If it can be rebuilt, and it is vital to rebuild, why not rebuild it somewhere else? It could fit in a museum or gallery and be viewed as a museum piece. And Mackintosh was a modern man: would he have wanted his destroyed library to be remade as a kind of model-kit version of itself? Or would his sensibility have demanded something new, something revelatory?

The opposing view - which has been articulated in letters to The Herald as well as comments on www.heraldscotland.com - is that Mackintosh did not build the library himself. It is not a work of art fashioned by his own hand. He designed it, and drew plans of it. These blueprints remain the blueprints and these are the guides to how the library can be conjured from the ashes. In this view, remaking the library is like restoring any other great piece of architecture or design. This library can be rebuilt and it will look roughly like it did when it was first built. The GSA seems to be set on rebuilding the library, based on Mackintosh's plans and photographs.

Mr Mullane will argue his case at a debate to be held by the Charles Rennie Mackintosh Society on September 25 at Queen's Cross Church in Glasgow. And at the forthcoming Venice Biennale Of Architecture, the first of two symposiums will be held to discuss the restoration of the Mackintosh Building, with the second being held next spring in Glasgow. The question will remain: remake something that is lost, or look forward and make something new?