“Contrasts of Form,” the retrospective of seventy years of geometric abstraction currently at the Museum of Modern Art, surveys a vast territory: seven decades, one hundred and seven artists, and two continents. [1] Yet the show doesn’t feel overstuffed or chaotic. The individual works reinforce and clarify one another as if in a one-artist show, and there’s a start-to-finish coherence generally associated with the really well-organized overview of a single career. Only in the last section, covering the years i960 to 1980, does one feel a drop in energy; it’s like an aesthetic slowdown.

In a way, “Contrasts of Form” is about a career—the career of an idea. The Cubists and some early abstractionists banished from their art the physics of reality: the sovereignty of gravity and solid, three-dimensional form. But the artists one sees in “Contrasts of Form” went further. They rejected all that was sensuously organic: texture, chiaroscuro, the natural processes of growth and decay. In this show one encounters the first European artists to conceive an art without ties to nature. And there’s something astonishingly clear and bright and lasting about their dreams.

Who in the nineteenth century could have imagined, considering the value artists from Courbet to Monet gave to the mutable and accidental in nature, that just after 1900 nature would begin to disappear from much of the best art? True, one can see, in the various attempts of the Post-Impressionists to stabilize nature’s shifting forms, the beginnings of a move away