At Annely Juda Fine Art, 23 Dering Street, London W1, until 22 April
It is recorded that Mondrian, when told in 1938 that Georges Vantongerloo - a former colleague on the journal De Stijl some 14 years younger than himself - was using curves in his paintings, 'replied with a grimace of disapproval: 'I might have known''.
Mondrian had broken with De Stijl in 1924 over the use of diagonals by its editor, Theo van Doesburg: he himself used canvases set on the diagonal, but not diagonal lines.
Vantongerloo, on the evidence of this exhibition, did not use diagonals at all, but it is clear that curves lay somewhere behind his creative urge, even during the period of some 20 years from 1918 when he followed an orthogonal path.
His first rectilinear abstract compositions are shown by his own drawings to have been squared up directly from earlier naturalistic work, and even such a strictly planar and orthogonal work as Airport Building: type A, series A (1928) is accompanied by a companion piece showing a curved armature.
But the most powerful works in this exhibition are those of an orthogonal, architectural character, including (and despite its title) the Construction of the relations of the volumes which derives from the equilateral hyperbola xy = k, of 1929, which was reconstructed in 1979 by Max Bill, one of Vantongerloo's most devoted admirers.
Vantongerloo felt the need to extend Mondrian's doctrine of Neo-Plasticism into the third dimension - and it is the dramatic and almost tangible sense of space which these quasi-architectural compositions convey that seems to be of most relevance today.
Generally there is a lighter, freer character to Vantongerloo's work than to Mondrian's, both in line and colour, which is very pleasant. This is particularly marked after the war, when it becomes universally playful, curvilinear and highly coloured - much of it in the form of three-dimensional constructions using perspex planes and tubes refracting and reflecting light.
And yet this was underpinned by a highly developed theoretical position that is not always accessible other than to initiates, and it is held to embody serious 'research' into colour and light of a virtually scienti'c character.
Vantongerloo became almost as much a thinker as a maker, with a very small output - so to have assembled 80 works (though often diminutive in size) for this exhibition is something of a triumph. He was the focus for a school of artists, particularly the British Constructivists of the 1960s: Anthony Hill visited Paris after the war and discovered Vantongerloo there (Belgian by birth, he was a Paris resident since 1927), much as Ben Nicholson and Barbara Hepworth had discovered Mondrian there before the war. There remains always a freshness and charm about Vantongerloo's later work, beneath which seriousness can be discerned, but that seems at odds with the weighty theoretical signiflcance imputed to it by Max Bill and others.
James Dunnett is an architect based in London