Clark is best known for his work on 19th-century Realism, and now he has come to Picasso to write its final chapter. Cubism is retrogressive in that it looks back to Realism's cause — its social cause, not its stylistic cause. It is suggested that Cubism is at base a revival of old modernism. Then after the First World War "Cubist space disintegrated . . . [as] Bohemia disintegrated . . . The long form of life that Bohemia had represented — represented by opposing — had been irrevocably destroyed." This "domestication" of Cubism is "to be regretted when set against the century's first hopes".

The Marxist dream for art was dying. Clark defines Marxism as the theory of how "bourgeois society . . . would come to grief". It is that. But for anyone who is not a Marxist, Marxism's real distinction is its yearning to bring bourgeois society to grief. Modernism gave up on the Marxist ideal — that is what we are supposed to see in the changing depictions of space by Picasso, the "artist of the century", who painted "the pathology of an age, not an individual". In Clark's formulation, true modernism is revolutionary, perhaps inseparable from Marxism. What is so precious in Cubist art is that the painter had "disappeared into the style". Picasso said, "We were trying to set up a new world order". With this book Clark hopes for nothing less than to "to keep a kind of resentment at modernism alive, in order to keep modernism alive" — to keep the struggle alive. 

Clark broadly approves of Clement Greenberg's assessment that "Picasso was a very great artist between 1906 and 1926 . . . But . . . a very uneven artist since then, and in the last twenty years [up to 1956] not even a good one on the whole". Greenberg attributed Picasso's decline to his "pursuing expressiveness and emotional emphasis beyond the coherence of style". I take the point; but it does not worry me. It seems right that a painter should pursue expressiveness and emotional emphasis. Coherence of style is the preoccupation of painters caught up in dogma — the sort of dogma that Greenberg liked to lay down for them. By now, I suppose, we have tired of that pretend valiant struggle against arbitrary, narrow, self-imposed artistic idioms. I suspect Picasso tired of it too; but Clark, of course, still believes in it — that is why he complains. 

During the 1930s, Clark feels Picasso's painting suffered "a massive drop in aesthetic temperature" — this would be the result of his having neglected the true modernist cause. Picasso began to draw and paint the old myths. "A token exterior has won." Or, as I see it, art has won. This is the point where Picasso becomes more interesting to me — I think I would rather look at the Vollard Suite etchings than any Cubist work. Picasso grew up into an artist, from being merely a modernist. Clark is indeed aware of another view of Picasso. He says perceptively of Guernica that "our culture clings to it, as if in reaction to everything else Picasso stands for." He may prefer Picasso as Nietzsche's painter, the unmoral painter, for ideological reasons, but nowadays most people do not. Most people, outside universities, want more from art than the embodiment of radical theories.