The paintings and drawings by Jo Baer, Mary Corse, and Agnes Martin in “At the Edge of Things” range in date from 1959 to this year, but all are grounded in phenomenology and investigations of borders. Corse has beveled some of her stretcher bars so that the paintings become wall-mounted plinths, extending out to meet the viewer’s gaze. Most of Martin’s vertical graphite lines in Untitled #12, 2002, do not touch the edges of the canvas but fade out near the top and bottom. An arm span of taut cloth becomes an arena for mental projection, as evinced by occasional titles (Gratitude, 2001, and Aspiration, 1960, for example).

In Baer’s work here, the edge is the primary site of action. The diptych Untitled, 1969, consists of two flat gray paintings. Strips of black paint wrap around the left and right edges of both components. Within each strip is the outline of a rectangle in another hue. These rhythmic intrusions stop short of the top and bottom edges by about an inch. Because of the significant value change between the gray and black paint, the canvas's hard vertical perimeters appear to soften into curves.

To engage in these visual games, a viewer must dedicate sustained attention to each piece; such absorption is generally difficult in our anxious present moment of environmental collapse, mass migration, and ongoing identity-based struggles. But optical interaction can also be understood as a process of negotiating boundaries, a technique as relevant to psychology and interpersonal relations as it is to phenomenology. Consider Baer’s diptych again: The very structure of the work reflects acts of comparison, inviting the this-to-that action so fundamental to the construction of the self. By reminding viewers of the inconsistency between embodied vision and material properties, these works suggest that boundaries are active, and always in need of re-evaluation and care.

— David Muenzer