What is American about American art? John Updike says it's lininess.

Lininess!

The liney/painterly dichotomy persists to this day, and in the century since [Winslow] Homer's last works it has taken many forms. The dry, burnished literalism of Grant Wood and Charles Sheeler followed the ebullient impressionism of Childe Hassam and William Merritt Chase. Thomas Eakins is liney, John Singer Sargent is not; Andrew Wyeth is liney and Edward Hopper not. Among the Abstract Expressionists, Jackson Pollock achieves his signature effects with a welter of lines, and Mark Rothko achieves his by blurring all edges. Among Pop artists, Roy Lichtenstein takes the comic-strip lines and Benday to a majestic scale, while Andy Warhol remains a colorist above all. All, it might be said, employ highly personal techniques to confront the viewer with something vitally actual, beyond illusion.

Two centuries after Jonathan Edwards sought a link with the divine in the beautiful clarity of things, William Carlos Williams wrote, in introducing his long poem Paterson, that "for the poet there are no ideas but in things." No ideas but in things. The American artist, first born into a continent without museums and art schools, took Nature as his only instructor, and things as his principle study. A bias toward the empirical, toward the evidential object in the numinous fullness of its being, leads to a certain lininess, as the artist intently maps the visible in a New World that feels surrounded by chaos and emptiness.

From the same issue of NYRB, the theme of perception, order, and chaos continues:

In fact, "external reality" is a construction of the brain. Our senses are confronted by a chaotic, constantly changing world that has no labels, and the brain must make sense of that chaos. It is the brain's correlations of sensory information that create the knowledge we have about our surroundings, such as the sounds of words and music, the images we see in paintings and photographs, the colors we perceive: "perception is not merely a reflection of immediate input," Edelman and Tononi write, "but involves a construction or a comparison by the brain."

Draw lines.