Exhibition: Consider the lilies of the pond

The Royal Academy's "Monet in the Twentieth Century" is an exhibition of dignified loveliness. Monet's paintings are sad and beautiful. They also appear rather lonely, though the Academy makes a good case for giving them a central role in the development of modern art. Indeed, everyone will be struck by the way that canvases in the last room of the show so resemble radical abstract painting in America in the late 1960s and early 1970s. The catalogue's wide-ranging essays discuss this phenomenon of the "abstract expressionist" Monet and also explore such subjects as Monet's love of London and interest in Turner, his ambitious gardening at Giverny, his feeling of Frenchness and his reactions to the tragedy of the First World War.

All these topics, and many more, are shown to be relevant to paintings which are almost exclusively of landscape subjects and which approach abstraction. We are reminded, yet again, that there is no such thing as pure painting. Pictures such as these, however diaphanous and apparently self-absorbed, are still drenched with personal and social meaning. Monet was a symbolist, though never a member of the symbolist movement. His paintings described what he saw, but he liked things to mean more than they appeared to mean. His haystack pictures of the 1890s were about the livelihood of the peasantry in rural France, and it is quite possible that the paintings of his garden are about life and death, the subject that absorbed Rothko, whose art concluded the major symbolist tradition.

What might be the wider significance of the exquisite paintings of the London Thames that Monet produced at the beginning of our century? One theory is that they reflect his disillusionment with the French state after the hideous revelations of the Dreyfus Affair. However that may be, we know that Monet was one of those Frenchmen who loved the British capital, and probably he noticed - being an artist who for years had studied urban scenes - that no great 19th-century painter had really attempted to capture London's character. Monet's Thames pictures are enormously better than the overrated "Nocturnes" by his friend Whistler. A comparison with Turner is more difficult. The English painter died in the year of the 1851 Great Exhibition, when London changed into a modern city. So Turner was remote to Monet. Monet none the less found him intriguing, as he looked at the river from his suite in the Savoy Hotel. Apparently Monet was critical of Turner's palette, while also appreciating his desire to catch the changing look of nature.

Monet's own palette is of course a marvel, from its brassy gold to faint lavender. He was the most seductive colourist of the original group of impressionists. Nature's hues and tints led him to be ever more adventurous in his use of colour, even to the verge of tastelessness. Here is a tantalising aspect of the RA exhibition. For no one can tell how Monet judged colour in his old age. He suffered from cataracts and other problems with his eyes. Contrasts of colour which appear for a moment to resemble German expressionist painting - and are in any case operatic - may not have seemed so extreme to Monet himself. The same with his handling. Brushwork can appear surprisingly coarse or enlarged, even though one senses the many decades of loving work that preceded such forthright application.

Monet was in his 60th year as the 20th century opened, and lived until 1926. He had always been a gardener. The mature development of his gardens at Giverny (where he had lived since 1883) is a central theme of the exhibition, since Monet found the motifs of his later work in the flower beds, terraces, pathways, ponds and bridges of his extensive demesne. I add that Monet was rich. When wealth comes to artists it sometimes ties them to the kind of work that had made them wealthy. Others find that worldly success liberates them from care and allows them to be extravagant in the studio. Monet was one of the latter. He was careful in his dealings with the world, conscious of his position as a great French artist. Yet in his studio and garden he could do exactly as he wished, with no rules but his own.

Could there have been an English, as well as Japanese, influence on the Giverny gardens? Certainly they are not on the Versailles pattern, as so many French gardens hope to be. At Giverny the only straight paths were adjacent to the house. There was no statuary. There were no fountains, yet it was still a water garden, adjacent to the river and spread around an elongated and mysterious water-lily pond. In this beloved garden it now became Monet's natural instinct to look downwards. Apart from pictures during a sojourn in Venice, the horizon and the sky disappear from his painting. His depictions of trees are disturbing. Trees naturally reach toward the sky. Monet's trees are always weeping willows, which also wish to return to earth and water. In these paintings there is a feeling of a memory of excavation, perhaps the experience of digging to make a pond or a channel.

Or even perhaps a grave. Without a doubt, Monet's paintings of willows were a response to the death toll of the 1914-18 war. So also were his elongated canvases and mural projects of the next years. It's interesting that Monet never attempted a really tall shape for a painting, though he extended canvas size lengthwards with an audacity that, even today, seems remarkable. I surmise that long pictures felt more appropriate because their format reminded Monet of death and the long processions of its rites of passage. He must often, at his age, have thought of his own death as well as the loss of innocent young soldiers, peasant boys from his neighbourhood, who had never known the pleasures and excitements of Paris.

His pictures are memorials of a special type, for the obvious reason that they are paintings and not sculptures. A social function of sculpture is to produce war memorials, yet modern sculpture has always failed when it attempts duties to the dead. It becomes dead itself. Monet's last paintings, which are totally unsculptural and wholly pictorial, are the best lamentations in all the visual art that described the 1914-18 war. And perhaps this is because their melancholy is so aesthetic. They do not ask for the last post to be sounded, nor for any person to be remembered. The paintings only record their creator's feeling that the modern world had come to its end.

Monet's amazing and heart-breaking final works are among the last flower paintings of any consequence in western European art. I think he instinctively knew this and may have suspected that, at the end of his own life, he was also at the end of art in general. Yet he could never imagine that his own work would ever cease. By the time of his death he had produced some 2,000 paintings. This abundance has a parallel in the number of plants in his garden, which was full to overflowing. The underlying pessimism of Monet's art was balanced by nature's capacity for renewal, and this is another lesson of the RA's unmissable exhibition.

`Monet in the 20th century': Royal Academy of Arts, W1 (information and advance tickets from Ticketmaster: 0171 413 1717), to 18 April. Sponsored by Ernst & Young.