ART / The still, small voice of turmoil: Andrew Graham-Dixon studies small objects of desire in the work of Giorgio Morandi

HIS NICKNAME was 'Il Monaco' (The Monk) and he spent a lifetime painting simple things: old bottles and cups and bowls and vases arranged in different configurations on a rugged wooden table-top in the flat that he shared in Bologna with his three sisters Anna, Dina and Maria-Teresa.

Giorgio Morandi (1890-1964), a bachelor with a reputation for reclusiveness, was the least hysterical of all 20th-century Italian artists. He knew the Futurists but never joined their maniac iconoclastic cult of modernity. He contributed, but only briefly, to Pittura Metafisica. Movements came and went, but Morandi just got on with the slow business of painting masterpieces and forged, out of his Franciscan devotion to poor and ordinary objects, an art that transcended the plainness of its subject matter.

'Giorgio Morandi: Five Paintings for Contemplation', at the Accademia Italiana in Rutland Gate, is the smallest and quietest art exhibition in London at the moment. It is not controversial or topical. No anniversary, of birth or death, is being spuriously celebrated. It is not An Event, nor does it pretend to be one. No tombstone catalogue, no merchandise, no rhetoric; just five pictures by a great painter hung simply and sparsely in a large white daylit room.

Morandi painted his pictures slowly, and they require the slow viewing that this show encourages (the white room contains chairs to sit on as well as paintings to look at). They do not yield much to the casual glance because to look at them quickly is only to see their mundane subjects, the glass or the cup or the vase. What counts as much is the way they are painted. Morandi's table-top ensembles are endlessly mobile, their surfaces worked and reworked to emphasise all the subtle slippages that occur between observation and the transcription in paint of what has been observed. One of their themes is the transfiguration of ordinariness. The paintings also propose their own subtle code for real things and create their own alternate worlds in order to reflect on this one.

Flowers, painted in 1950, is a small picture that strands a single vase containing roses on a light table-top against a dark wall. The knobbly vase could be made of cheese but it also has the scale of something enormous, a tower or a lighthouse. The flat bands of wall and table-top are painted both pastily and abstractly and they evoke the enormity of a long empty beach and a long empty sky. Morandi made great art out of small things and one of the ways he did so was by making small things seem physically vast, metaphorically charged. A room containing a vase on a table becomes a landscape containing a monument.

Painting makes up its own version of the truth. To the right of the vase a shadow falls and trails away, a dwindling river of darkness running off the edge of the canvas. Fugitive, it bears no relation to a real shadow and has become instead a thing in its own right. The shadow that looks as if it has leaked out of a thing like a fluid is a Morandi hallmark, announcing the bold self-sufficiency of his art and the necessary liberties that all art always takes with facts. In Flowers, the curving, uneven line of the shadow is taken up in the thin blue lines that run up and girdle the vase: decorative motifs that, remade in painting, have become wonky and tremulous.

The hesitancy of those blue lines is important, because Morandi's art as a whole invests hesitancy with tremendous significance. Hesitant painting - and the texture as well as the line of Morandi's art speaks of hesitancy, full of undisguised retouchings and alterations - becomes a model for hesitant- looking and a way of saying that things can always be looked at differently. The moral of Morandi's painting is: take nothing for granted. Even the simplest things (just a bunch of flowers on a table lit by the afternoon sun) can become, looked at for long enough, an image of the mute mysteriousness of all things.

Objects lose their individuality and become part of a continuum of change, or at least Morandi's equivalent for the idea of constant change; they become absorbed into the busy shifting field of artifice that is the picture. Air is made as present to the eye in Flowers as solid objects. Move in close and you see the whiplash scribble of brushstrokes that is the artist's way of painting nothing at all; not thin air, exactly, but air that has been thickened, like the heat haze that rises off tarmac in high summer, blurring the edges of things seen through it so that they appear as if viewed through half-closed, tearful eyes.

Morandi makes the static image eloquent of volatility and mutability and he creates a world where everything literally flows and seeps into everything else. Background becomes foreground and foreground becomes background; air solidifies and solid things liquefy. While his vase has the soft fatty quality of cheese left out in the sun, the roses that it contains, stemless and bunched together, look like soft scoops of melting ice-cream.

Morandi uses the molten quality that paint, itself a liquid medium, can so readily impart to representation. There are many hints of this in earlier painting - the creamy surfaces of Chardin; the thick dribble of paint that Jacques-Louis David allowed to trickle down the top left-hand edge of the crate upon which the dead Marat rests his hand - but Morandi uses the liquidity of paint to speak of transience even more insistently. He uses it to propose a congruence between the unreal world of painting and the real world - to suggest that things really are as fluid and as unfixed as his images of them, even if they do not always seem so.

Still Life, 1956, is a painting of three opaque, square wine carafes that also makes objects seem far bigger than they are, although its monumentality seems invested with a different significance than that of Flowers. They look like three houses huddled next to one another and perhaps this is intentional. Perhaps the painting is meant to offer up an image of inanimate things transformed into an image of society, of human contact or the lack of it.

Morandi's characteristic wavering line - the line of hesitancy that he inherited in part from Cezanne - is most apparent here in the way that he has unevenly traced the thin gaps that separate these objects. Here, line acquires a different form of pathos. The forms in the painting touch, barely, only to separate again. If Flowers is about merging and mingling, opposites turning into one another, this is a picture about the gaps between objects (and maybe people too: there is something anthropomorphic about these flesh-coloured long-necked carafes), about sad separateness. Unexpected poignancy is found in the simple distinctness of things.

Morandi's art has a reputation for calm and orderliness that the paintings in this show contradict. They are as intense as the sharp stab of an emotion and their apparent composure turns out, on extended viewing, to be nothing of the kind.

The objects on Morandi's table-tops are precarious, tipped forwards by a flattened perspective that recalls trecento painting, or pitched sideways by a horizon line (in Flowers particularly) that is subtly out of true. The object monuments and object cities teeter and tilt, the surfaces of the paintings churn like seas of butter. Morandi's world is not still, but forever in motion. The Monk practised a form of violent contemplation.

'Giorgio Morandi: Five Paintings for Contemplation' is at the Accademia Italiana, Rutland Gate, London SW7, until the end of the month

(Photographs omitted)