I recently asked a middle-school class if they preferred sandwiches cut in half diagonally or lengthwise. The classroom erupted in a passionate argument: triangles versus rectangles. Everyone had a vehement preference.

Very few students, however, had a practical reason for their opinion. They just liked one shape much more than the other. Triangles are delicious. I’m not eating some stupid rectangle.

How do we come by these essential preferences, and how much do they influence our decisions, from slicing a sandwich to buying a house? Surely there must be formative objects and spaces in one’s past, probably so early that one can’t remember them, which cast shadows over our future decisionsimpressions that travel with us, unseen, haunting us.

PERSONAL GEOMETRY

Chapel Hill-based artist Casey Cook‘s Geometric Desire, showing at LIGHT Art + Design through Nov. 29, mulls and mills such fundamental images. A conventional description would state that the show includes paintings, monoprints and cardboard sculptures ranging in scale from tabletop to towering. But it’s more accurate to say that it includes a right-angled zigzag shape, a teardrop-shaped hole and a rolling form that could be either a cloud or a stylized series of hills.

Cook represents and recombines these three shapes in different contexts, across various media. “Whoa Nelly” is a 14-foot, white cardboard floor sculpture that looks like four rolling hills seen from a distance. The same shape reappears atop a tree-like sculpture called “Quarrelling with Normal,” where it could be a cloud or the tree’s foliage.

The right-angle zigzag (frequently in orange) appears in multiple paintings done in the kind of tempera paint used in set construction. “Squirt” depicts a pair of these blocky orange lines emerging from a slot. In “Throbbing,” the head and foot of the line are shortened to make it a vertical symbol, like a numeral 1 or lowercase l.

Cook denies us pictorial reference between these shapes and any personal reference or literal source. Their iteration throughout the show is intuitive rather than programmatic. But she offers some clues in her titles.

The teardrop hole in the middle of a candlestick-like vertical shape represents hunger, as if it were an empty stomach. “Measurements of Time, Tools of Hunger” is an 8-foot-tall, white cardboard version of this shape. Cook then used the cutout tear to make a blue monoprint on canvas called “How Long Can Someone Survive Without.” The full figure appears again in blue paint on a small cardboard panel as “Hunger Pang.” A pair of sculptural tears, painted silver and hung on the wall, is called “Cold Shower.”

Cook’s simplified lines look familiar. The curved profiles of her cardboard sculptures are reminiscent of Matisse’s paper cutouts. Keith Haring‘s distinctive outlining is visible in the more rectilinear forms in Cook’s paintings. She escapes being derivative, however, because these components are means toward Cook’s own ends, showing the substance within the shapeseven if the substance cannot actually be named.

In this respect, cardboard is a particularly expressive material for Cook. She makes its corrugated interior structure visible in large, bright tempera prints onto canvas. Applied excessively in order to get a good print from cardboard’s inconsistent, absorbent surface, the paint leaves Rorschach blots that speak to the idea of meaningful association in the absence of discernible reference.

The large cardboard sculptures are the highlights. They’re deeply satisfying visually. You kind of climb them with your eyes, as if you had been turned into a child and your toys had become real.

The painting “Unlearn Everything,” with text that reads “for mommy,” provides a key. Cook is working her way back toward her original shapes, figuring out the nature of her relationship to the line and the angle, the curve and the hole. She’s trying to turn a haunting into understanding.

THE SUPERNATURAL EXPOSED

A few blocks away from Cook’s show, in a tiny exhibit at UNC Chapel-Hill’s Ackland Art Museum, a different kind of haunting is undone through understanding. The eighth installment of the Ackland’s “Adding to the Mix” series, William H. Mumler’s “Mrs. W.H. Mumler, Clairvoyant Physician” (1870s) (through Jan. 4), features a spirit photograph on a carte-de-visite as well as 10 paintings, engravings, lithographs and more that depict beings from the beyond.

Spirit photography purported to capture invisible spirits. Mumler was the earliest and best-known creator of these doctored images, teaming with his wife, Hannah, who is depicted here as being visited by her “controlling spirit,” Dr. Benjamin Rush, a signer of the Declaration of Independence.

Rush appears as a barely corporeal white form behind Hannah, placing one hand on her head. She sits “entranced” with eyes closed and hands folded on her lap. It’s not particularly different from Mumler’s most famous photograph, in which a vaporous Abraham Lincoln stands behind the widowed Mary Todd Lincoln. Spiritualists ate this stuff up well into the 20th century, even after the darkroom trickery behind the images was common knowledge.

Mumler and his followers were eventually debunked. He and his wife fled Boston and a ruined reputation in 1868, only to fight fraud charges in New York. They returned to Boston and set up Hannah as a medium in order to take commercial advantage of whatever believers remained.

The rise and fall of spirit photography provides a view of the spread of science across the larger American population. Mumler’s generation was the turning point when widespread belief in the supernatural became the province of a dwindling few.

Several other images are of literary scenes. In James Parker’s 1805 engraving, Ulysses cowers in Hades upon encountering the ghosts of old war buddies that “stun my scar’d ears and pierce hell’s utmost bounds.”

Much gorier is Louis Boulanger’s 1830 lithograph of a condemned man from a Victor Hugo novel. Three guillotined specters visit his cell, carrying their severed heads in their hands like bowling balls, their fingers hooked into grimacing mouths.

American artist Juan Logan provides the most recent imageand the only one divorced from representationwith a work from his 2009 Ghosts series. Logan airbrushed ground, the fine gradient used for shadowing in an etching, onto a plate where he had placed antique slave shackles. The resulting image has a vague, dark figuration to it. It gives an uneasy impression even before you read the gallery text and learn about the shackles.

It also provides a lesson that Casey Cook could affirm. The unseen is nothing to worry about. The worrisome or fascinating thing is to see something clearly but not know what it is.

This article appeared in print with the headline “American spirits”