Exhibitions: An eye for the ladies

Some artists appear to have been incapable of painting a nude. Van Gogh, for instance, couldn't do it. One attributes such reticence to his strict Protestant background, even though his upbringing didn't keep him out of the whorehouse once he had left the family rectory. Another painter who avoided nudity was John Singer Sargent, Van Gogh's near contemporary (he was born in 1856, van Gogh in 1853). We cannot tell from the Tate exhibition whether Sargent had any religious feelings at all. It's clear that he liked the company of women and the way that they looked. He often used professional models and luxurious interiors came naturally to his brush.

He wasn't a prude, yet direct and sensual depiction of the body was still not to his taste. This remains a puzzle. Perhaps he was shy of the undraped figure because of an early failing. Sargent trained at a time when drawing from statuary, or in the life room at the academy, was pretty well de rigeur for any student artist. My guess is that the young Sargent wasn't very good at the drawing discipline, so put it aside for ever. There are no drawings at all in the Tate's comprehensive exhibition until we come to some awkward studies from around 1909-18. They look like the work of a man who had been asked to repeat a lesson from his distant schooldays, then found that the lesson had been long forgotten. Sargent did everything with his brush and the brush did everything he wished. The gods so munificently bestowed him with this painterly gift that one scarcely notices that he had no command of line.

These moustachioed Edwardian gods gave Sargent his brush to represent clothing rather than the body. Hence an absence of frankness in his art, however bold the application. Obviously he was a connoisseur of clothing, as all society portraitists must be. Today, most lovers of art will have lost contact with the niceties - and, sometimes, the provoking haughtiness - of expensive dress in the 1890s. We can still appreciate the finery, and that's because the brush tells us that appreciation is in order. We know that the whole business of fashionable dress is artificial, while also knowing that skilful painting at the turn of the century was good at showing a love of artificiality. Photography could not compete. True to his calling, Sargent was rather aloof toward the camera.

The handling is what counts in any good Sargent picture, followed by the orchestration of colour and light over a pretty wide area. He's better painting big rather than small, never uses a horizontal shape without unease, and evidently had a liking for a sizeable tall canvas. Here is the shape that gives us two of his masterpieces, the Tate's W Graham Robertson and the National Gallery's Lord Ribblesdale. Sargent never produced an original composition in his life, but this elegant use of a tall format (found elsewhere in late 19th- century art) gives an up-to-date visual flavour.

The tonality of the portrait of Ribblesdale (the Master of the Queen's Buckhounds, he will have you know, for he poses in riding clothes, with his whip) comes ultimately from Velsquez. More immediately, it comes from Sargent's Parisian tutor Etienne Carolus-Duran, who loved the Spanish master, and who took Sargent away from his more academic studies to teach him how to be flash and respectful at the same time. Carolus- Duran was close to Impressionism yet lacked the aesthetic courage to be an impressionist. The same with Sargent. He could feel the merits of Monet and Manet, whom he knew. Up to a point he was able to reproduce their excellence in his own work. He did not however believe, as they did, that painting per se had a cause in the world. Sargent's impressionist paintings at the Tate are no more than friendly exercises.

The route of the avant-garde was of no interest to him. Worldly and multilingual, as much at home in the salon as the studio, he married modern art to the ruling classes. Such a union is bound to disfavour art, but there we are. The results of Sargent's compromise are unmatched by any other society painter of his time: his best period, that is to say, in the society of riches before the First World War. For years, Sargent remembered the licks and nuances of Manet. In 1892 they reappeared, with just a little tickling of aestheticism, in his portrait of Lady Agnew of Lochnaw. Who is she? Not much caring myself, I recommend the informative catalogue by the curators of the show, Elaine Kilmurray and Richard Ormond.

I do feel curious about a handful of portraits of writers. Likenesses of dressed-up aristocrats don't tell us much about them as people. We do however know writers. We read their books and can match an artist's interpretation of their character with our own views. In this area Sargent is at his most interesting. His portrait of Henry James is classic. One cannot imagine any other resemblance of the novelist with such authority. At the same time Sargent is uneasy. The painting doesn't have the feeling of his personal signature. He might have been more relaxed if painting a woman.

A whiff of bisexuality continues in pictures of other writers, primarily the thinly-painted Vernon Lee and Robert Louis Stevenson. "Vernon Lee" was the pen-name of Violet Paget. Looking at this casual, affectionate picture, one does not know the sex of its subject. The Stevenson portrait is painted in the same sketchy manner. I belong to the RLS Denigration Society, which welcomes new members. We hold that Kidnapped coarsens everything good and wise in Walter Scott and that Treasure Island is a disgusting paean to the greed of colonial capitalism. These books should never be put into the hands of children. Sargent does not commemorate Stevenson as a writer. Instead, he catches the cunning yet brave way in which Stevenson coped with his illnesses and dodgy career.

A Sargent portrait of Oscar Wilde, whom he knew, might have been a super late work! Alas, Sargent in his final phase had to be a war artist. The huge mural-like picture of gassed soldiers in the last room of the Tate exhibition might be by another artist. It lacks every bit of Sargent's style as formerly known. This is a moving picture about the Kaiser's war which makes us think that, in old age, everything done and finished, he might have painted male nudes.

'John Singer Sargent', sponsored by Morgan Stanley Dean Witter, Tate Gallery, SW1 (0171 887 8000), to 17 January. Advance tickets: 0171 420 0055 (pounds 1.60 booking fee).