The theme of the exhibition is 'French Landscape Painting 1874-1914', but the works of art that it contains are presented under such diverse and often confusing rubrics that the result is a largely incoherent jumble of insensitively hung pictures. Its didacticism is made even less appealing than it might otherwise have been by the fact that Thomson belongs to the growing tribe of modern art historians who believe that the primary interest of paintings is sociological and who are thus liable to interrogate Matisse's paintings of the South of France, say, for evidence of the increasing urbanisation of the Cote d'Azure in the early 20th century, or to treat Monet's paintings of poplars as invaluable documents of the development of the French logging industry in the 1890s.
Somewhat perversely, given the ostensible theme of the exhibition, the first pictures to be seen in it are depictions of Paris and its suburbs. It turns out that Monet's slight and rather Constable-like oil sketch of The Seine at Petit- Gennevilliers, Matisse's muddy and clotted early painting of barges passing the Cathedral of Notre-Dame, Seurat's tiny, sparkling pointillist picture of the Eiffel Tower and a large number of other pictures of the Parisian metropolis, its landmarks and its outskirts (mostly by considerably lesser artists), have been assembled to do little more than demonstrate the swift pace of urban development in turn-of-the-century France. The point could have been made rather more economically and should have been, partly because it is such an obvious one, and partly because it relates so obliquely to the declared subject of the exhibition.
It is also unfortunate that the primary thesis which these pictures have been brought together to justify (it is necessary to consult the catalogue in some depth to realise that this is, indeed, why they have been brought together) seems both somewhat strained and somewhat facile. French artists of the late 19th and early 20th centuries, Thomson suggests, were both fascinated and terrified by the accelerated change in their world brought about by the advent of modernity. They were drawn to paint the Eiffel Tower because it symbolised the new world of glass and steel which they felt, for better or worse, was about to engulf them; and they were drawn to paint those suburbs because they were the places where the old and new worlds, of nature and the spreading city, visibly collided. In painting such motifs, Thomson argues, artists involuntarily revealed both their own anxieties and the greater anxieties of their culture.
The elaborate and precarious edifice of his argument rests, to a great extent, on a distinctly eccentric interpretation of Seurat's nearly abstract painting of a field of sprouting alfalfa plants, painted in 1884-5. The spatial ambiguities created by Seurat's pointillism - which has resulted, here, in paint that looks like basketwork, a flat field of marks standing in for the fertile field of alfalfa - makes it hard to distinguish just where foreground becomes background, where the field, which takes up three-quarters of the canvas, meets the road and the buildings behind it. Thomson argues that this spatial indeterminacy betrays Seurat's troubled attitude to the incursions of the city into the country in his time. This is both ingenious and foolish, and it seems a strange coincidence that the concerns and anxieties that Thomson imputes to Seurat - a deep interest in the sociological implications of the urban landscape - should be of just the kind that might be expected to preoccupy a late 20th-century person (an academic, for example).
The title of the exhibition turns out to be both opportunistic and something of a false promise. 'Monet to Matisse', catchily alliterative and unashamedly populist, a title that must have been dreamt up by someone in marketing rather than Thomson himself, suggests a show that wants to provide balm for the eye and mind, a brief interlude of pure visual pleasure in the busy lives of busy people. In fact, the exhibition is hard work and is meant to be. The intellectual Puritanism that lies behind Thomson's attitude to pictures - the notion that they are not things to be enjoyed but things to be understood - has some disconcerting side-effects. One of these is the strong impression, in certain sections of the show, that particular masterpieces of French landscape painting have been included specifically in order to be disapproved of and tut-tutted at. The most radiant wall of pictures in the entire exhibition, on which hangs Cezanne's The Sea at L'Estaque, Gauguin's Martinique Landscape and Matisse's L'Acanthe, is in a section of the exhibition devoted to 'The Classical Landscape'. Referring to the relevant passages in the catalogue, the viewer is encouraged to disapprove of the bourgeois escapism of such pictures, which may be 'delightful' but which are also 'complacent' - to note their failure to confront the real, pressing social and political issues of the day.
But pictures cannot be completely denatured by the ways in which they are hung and the ways in which they are written about, and visitors to the show who lack the time or the patience to read the catalogue in its entirety need not be distracted by such urgings to think of great art in such simple-minded, dry, inhumane terms. They are more likely to note the flickering, nervous hesitancy of Cezanne's seascape, the uneasy and tremulous nature of his classicism, his yearning for the old harmonies of Claude and Poussin and his fertile inability to recreate them; to sense the compulsive need to find a new way of painting, to escape what had become the academic realism of late Impressionism, that lies behind the bright patchwork of Gauguin's exotic landscape; to admire the mad and beautiful freedom with which Matisse dared to reinvent the world in paint.
The failure of 'Monet to Matisse' lies in a deep misunderstanding of the nature of French art of the time. There is something inherently shortsighted in the very idea of an exhibition devoted to a single genre or motif, such as the landscape, in early modern art. This is precisely the period that sees the death of the conventional hierarchy of genres (history painting, portrait, landscape and so on) and which makes the painter's own struggle for self-expression the true theme of art. Attempting to deduce Van Gogh's attitudes to the agrarian poor in the South of France from his paintings of reapers under burning suns is a necessarily pointless activity. Whatever Van Gogh painted, Van Gogh was his subject, and the same is true of just about every substantial artist whose work is included in the show.
At a more specific level, embarrassing errors of judgement are made. At one point, late in the show, it is suggested that the only artist in France to respond with genuine inventiveness to the new world of speed and shifting perspectives that arrived with the invention of the aeroplane was the eminently forgettable painter of panoramic bird's-eye-views, Andre Devambez. But what was the Cubism of Picasso and Georges Braque - both of whom were obsessed with aeroplanes and aviation, and whose nicknames for each other were Orville and Wilbur, after the Wright Brothers - if not a complete and giddily airborne exploration of a new pictorial space? Devambez painted views from the air with dull, unimaginative literalness. Picasso and Braque made painting itself dizzily swoop and fly. The omission of their work - and, what is perhaps even more extraordinary, the almost complete omission of Cubist art from a show nominally devoted to French art between 1874 and 1914 - is characteristic of the clouded thinking that lies behind the entire exhibition.