Visual Arts/Reviewed today:  The Widening Gyre, Rubicon Gallery, Dublin, until October 2nd (01-6708055); Gemma Browne: Twinkle , Kevin Kavanagh Gallery, Dublin, until September 25th (01-8740064); Olivia Musgrave , Jorgensen Fine Art, Dublin, until September 25th (01-619758) and Quire, Graphic Studio Gallery, Dublin, until September 25th (01-6798021)

Invited by the Rubicon to curate an exhibition, Patrick Michael Fitzgerald has come up with The Widening Gyre, a show of paintings by five artists. Fitzgerald, himself a painter, has been based close to Bilbao, in northern Spain, for a number of years. Before the opening of the Guggenheim museum there, Bilbao had nothing like the cultural profile it now enjoys, although Fitzgerald has remarked that, even without Guggenheim, he found it a good place to be. This show provides an indication of the way he sees himself in a European context - and the term European here could well include New York.

The five painters he asked to take part share no obvious stylistic straits. They might, though, share a conception of what painting is or might be. Fitzgerald's Yeatsian title, taken from The Second Coming, precedes the poem's most famous lines: "Things fall apart; the centre cannot hold / Mere anarchy is loosed upon the world." For Fitzgerald, one feels, artists necessarily occupy a space where the centre has not held and cannot hold.

In fact, as he puts it, painting itself "is a centre which cannot hold, in different ways". So these painters make "precarious structures" that allow for an underlying tenuousness or uncertainty.

All this might sound a bit dry and cerebral, but one of the fascinations of painting is that it is a physical medium, and ideas are tempered in the painters' engagement with physical materials. Elisabeth Vary addresses this physicality in her irregular, boxlike works, applying a gestural painterly vocabulary, usually seen in relation to an integral, flat, rectangular surface, to fragmented, sculptural forms. And does so while maintaining a sense of a frontal, painted image.

In painting, gestural is usually taken to imply uncontrolled, largely because of a widespread misunderstanding of the nature of abstract expressionism. Gerhard Richter has devoted substantial energy to demonstrating that the supposedly subjective, expressionist gesture can be incorporated in a scheme of icy, controlled rationality. There is a comparably measured quality to Vary's painting and even to the extravagant displays offered by Adrian Schiess and Rui Patacho.

Schiess's swathes of pigment and his titles invite associations with landscape. But the overkill of Ciel En Août, its surface dotted with nodules, takes it into another realm. And, by being too much, it works. Patacho's palette is less landscape-related, and despite his spontaneity his work is cooler, more to do with process.

Thomas Nozkowski is altogether more measured, emphasising a mix of the arbitrary and the designed in pieces that invite interpretation but don't open themselves up to it. The same could be said of the work of Juan Uslé, who, as it happens, is the subject of a major show at the Irish Museum of Modern Art at the moment. Predicated on uncertainty as it is, The Widening Gyre is surprisingly user-friendly, a good introduction to some possibilities in contemporary painting.

Gemma Browne's previous exhibition Being Pretty Is Everything marshalled a series of head-and-shoulders paintings of teenage girls. Each was clearly a separate, distinctive individual, but there was also an eerie sameness to the images, which suggested that all the subjects were aiming for a single ideal.

There was no sense that Browne was adopting the moral high ground or editorialising about the pressure girls might feel to conform. The overall effect was more ambivalent than that, more deliberately inconclusive, not least because each individual looked poised and self-confident.

Now, for Twinkle, at the Kevin Kavanagh Gallery, she has produced a similar though subtly different body of work. There is, again, a uniform, head-and-shoulders format, but this time around the figures are dolls. They are younger than the teenagers in Being Pretty Is Everything, with big heads and huge eyes, much more childlike. But they are fashion playthings, heavily styled and made up.

Rather than their eyes uniformly staring straight at us, as before, they look at us or obliquely to either side. Browne paints in a free, informal manner, lending a softness to the images that enhances their living quality. To their owners, dolls can come to seem alive, to have personalities. They can also be slightly creepy for that reason. Browne plays on these qualities. Her dolls look alive and very self-possessed.

The Japanese painter and sculptor Yoshitomo Nara has made a great deal of work featuring comparable doll-like creatures. His cartoonish figures are beautifully made, whether in two or three dimensions. Mingling aspects of dolls, children and adults, they come across as belonging to a race apart, and, while they are on one level engaging, there is something incalculable and even sinister about them. As with Browne's dolls, it is their air of removed, indifferent autonomy that gives them an edge.

Olivia Musgrave, showing sculpture at Jorgensen Fine Art, has built up a distinctive subject matter of her own through her interest in the Amazons, the female warriors of Greek mythology. In fact Musgrave, with her Greco-Irish parentage, delves continually and fruitfully into classical mythology for her subjects. There is a lightness of touch to her treatment of narrative and character, a humour that is vitally underpinned by a terrific sense of form and elegance of line - she is a very good draughtswoman. Her formal language probably owes most to 20th-century neoclassical Italian sculptors.

She is by now thoroughly at home with her Amazonian combinations of female nudes and horses. Even when wielding spears her warriors are not as fierce as you might expect, and they seem to lead sociable, agreeable and, most of all, horse-loving lives.

Second Horses, in which a rider leads a second horse, is a beautifully poised piece of work. She is generally good on figures, whether human or animal, and the show also features several heads of the mythological characters Daphne, Artemis and Chlyte. There is tremendous life and expression to these heads. Despite the mythological emblems they incorporate, very effectively, they are presumably based on life, because they come across as being closely observed. Musgrave adheres to a classical tradition that always has a freshness to it.

Quire, at the Graphic Studio Gallery, marshals sets of prints by Marc Reilly and Kelvin Mann. Reilly's aquatints and etchings are dreamy recollections of a summer holiday on the Avonmore river in the 1960s. Not that they are illustrative. Rather, one could say that he sets about creating a series of meditative spaces, moving through a restrained chromatic register from print to print, consistently indicating hallowed moments in time with linear silver loop.

Mann's jokey, surreal images conjure up odd, obsessive characters in a world of eccentric contraptions: cycles on cable lines, horizontal towers. The overall suggestion is that the world we take for granted may be a weirder place than we imagine.