Raoul De Keyser at David Zwirner Gallery and Sarah Crowner at Nicelle Beauchene

Framed by the conventional whiteness of an unframed white canvas on a white wall is an open black rectangle. (The white is conventional in the sense that the axioms of Euclidean geometry are conventional.) Inside that rectangle, which is inside Raoul De Keyser’s painting The Chir, is the formal space where the rest of “Freedom,” his current show at David Zwirner Gallery, takes place.

Another open rectangle, this one tall and thin like a dressing mirror, stands on a white floor defined by another black line, leaning against what looks like a wall, except that in the upper part of the painting what ought to be that wall’s corner seems to have fallen down. This small conflict neither creates the optical dissonance you’d expect if it were more blatant nor shatters the Euclidean room completely, though a shallower space of overlapping shapes or interlocking lines is also possible. It doesn’t break anything—it merely bends. Instead of pushing his Platonic shapes and well-polished painterly techniques in new directions, Mr. De Keyser gently pulls at them, creating space, like the God of the Kaballah, through recession.

This vacant new space isn’t large: it has room for only a formal allusion to natural colors—grass green, sky blue, solar reds and yellows—and a few spectral lines and angles, which combine in delicate movements that are difficult to see. In No Title (8 Verticals/5), where vertical lines of yellow cross horizontal streaks of black, one thicker black line could be the horizon, but the rest remains unformed and void. In No Title (8 Verticals/6), seven sketchy red lines could be bloody fingermarks descending the canvas, or fiery spirits rising up, but they aren’t yet either: they’re in an amorphous state that precedes decision.

The most defined shape is a circle. In No Title (8 Verticals/7), an open circle of blue-on-red—a rigorously constructed ultramarine—inhabits a pale, blushing void, while in No Title (8 Verticals/8), a red disc is protected by a white buffer and incomplete black border from a darker, area of pink. In Falling Balls, white-on-white circles float in a different, red-bordered room; in The Failed Juggle, they burn red like a rash; and in two cases they even join with thick black lines to make vermicular, Munchlike figures. But the appeal of the circle—in addition to the reference to Zen painting—is that it’s the least definite of definite shapes, the best way to render substance without form.

In Double Crossing (8 Verticals/4), an arrow the color of dried blood, made of two lines that don’t quite meet in a point, crosses to the right, while another arrow, this one a mere shadowy darkness in the white void, crosses to the left beneath it, making a pair of guillemets collapsed together: the only thing being said is that something is being said.

Raoul De Keyser at David Zwirner Gallery and Sarah Crowner at Nicelle Beauchene