Collection of gifts in the making

When you visit the RHA Gallagher Gallery at the moment, it seems as if the Limerick City Gallery art collection has been miraculously transposed root and branch to the Gallagher in Dublin, which is, fortuitously, one of the few venues capacious enough to accommodate it. In fact, the show's curator Paul O'Reilly (he is also director of the City Gallery) assures us, it isn't by any means the whole collection - it just feels that way.

The sheer scale of the enterprise is breath-taking. But then O'Reilly, one of the great individualists in the Irish art world, is no stranger to taking on projects that would give pause to people with more staff and bigger budgets at their disposal. His gritty determination and his can-do, hands-on contribution to EV+A is almost legendary at this stage. And he lives up to his reputation for idiosyncrasy with the apparent grandiloquence of the title of this show, Kingdom of Heaven. He quotes Matthew 13: "Every scholar, then, whose learning is of the kingdom of heaven must be like a rich man who knows how to bring both new and old things out of his treasure house."

Sure enough, Kingdom of Heaven is a non-stop dialogue between things old and new from the treasure house of Limerick's City Gallery. It includes an image that features on the cover of a very handsome catalogue, a Nigel Rolfe photograph of a hand proffering a sheet of gold leaf, symbolically "extending an offer", as O'Reilly interprets it, "giving over something precious". For, he explains, apart from the commercial transactions inevitably involved along the way, a work of art is "a gift in the making by the artist and, once given over, in the remaking by the audience".

This is seasonally appropriate, and in fact there is a fitting, if overwhelming generosity to the display, which is arranged thematically rather than chronologically. Hence, there is a formidable battery of portraits, from 18th-century oils to 1980s photographs. Like most things in the show, they are captioned in batches, which encourages you to look at them without the prejudice engendered by knowing who painted, sculpted or photographed them. One portrait is intriguing titled Stella, that is Jonathan Swift's Stella, and attributed to Charles Jervas.

But the catalogue note quickly backs away from confirming either attribution, readily admitting that firm evidence is lacking. But Jervas was a friend of Swift's and painted him several times, and the sitter, while strongly characterised, has that wan look for which the painter was often criticised, so who knows? It is certainly a good painting.

O'Reilly's method could be described as setting the Modernist cat among the pigeons of traditional representation. In the catalogue, he gets the chance to engineer some pointed juxtapositions, seamlessly interposing a Gavin Hogg maze between landscapes by Maurice Wilks and Frank McKelvey, for example, or having a beautiful Sarah Purser landscape merge into a John Shinnors. The surface drama of a Ronnie Hughes abstract finds an unexpected pendant in a Letitia Hamilton landscape.

Beyond setting his audience the examiner's failsafe request to compare and contrast, does O'Reilly's editorial approach have more specific aims? For those wary of modernity and abstraction in art, there is the opportunity to see a commonality of aim, some shared level of language, between representational and non-representational work. It's strikingly clear that Hamilton and Hughes, for example, use similar means to bring life and interest to their surfaces.

The danger of this kind of approach is that incidental resemblances or points of correspondence can seem more significant than they are in fact. But O'Reilly is generally a canny observer. It looks as if the Hogg is sandwiched between the two landscapes by Ulster artists simply because it happens to have a horizon line, or what could be construed as a horizon line. But then O'Reilly could reasonably argue that he is underlining the formalism of the notionally "natural" landscapes by bouncing them off each other, and off the more overt formalism of Hogg's symbolic landscape, which is pretty much what happens.

It is in relation to this game of look-again that the book is an essential accompaniment to the exhibition. It's also a mini-exhibition in itself, with a high standard of colour reproduction and several extensive gatefolds.

Reproduction cannot, of course, take the place of the real thing, and the show throws up some unexpected treasures. These include a superb Anthony O'Carroll, donated by the Contemporary Irish Art Society, a very good Deirdre O'Mahony from 1996, Cormac Boydell's ceramic Garden, a de Kooning lithograph and Jim Sheehy's crisply made prints. ET