By For painters, the road to frustration is paved with pictures devoted to the “mystery of life.” Too often the results look like symbol soup or abstract minestrone, depending upon the chef. Artists do best when they stick to what they know: Michelangelo found spiritual depth in the male torso, Caravaggio in a wall streaked with light, Rembrandt in his own craggy face, Rothko in the color purple. Whatever the choice, painters should think globally, paint locally.

Photographers tend not to philosophize, perhaps because their lenses have a built-in commitment to visual reality. American James Nicholls is a notable exception. He admits to thinking “globally,” so to speak, when he took his extraordinarily arresting photograph of a canal near Agen in the south of France.  Engineered as a short cut between the Atlantic and the Mediterranean, the canal was put out of business by the coming of the railroad. Its purpose gone, the canal became as it is today—a quiet slip of water passing through the countryside bringing reminders of the ocean.

On one gorgeous June day, Nicholls stepped onto a small landing platform used as a boat dock on the canal and saw a perspective so miraculous he must have rubbed his eyes: The lush green foliage and its reflection seemed to cut the scene in two. Nicholls had previously photographed images of water and lines converging in the distance as separate subjects, but this was his first opportunity to show both in the same picture.

Toward the canal’s left side Nicholls discovered a point where the edges of the trees lined up with their reflections in the still water. He further disguised the recession into space by squaring off the trees at the top. Now, as far as his Leica was concerned, the deep foliage was a shadow mysteriously blotting out half of the sky. Landscape master Paul Gauguin advised artists to “study the silhouette of every form.” “Clear outlines,” he said, “are the mark of a decisive hand.” Nicholls followed suit, using the optical illusion to break the picture into a pair of rectangles, then throwing in a bright green wedge like a chevron painted by Kenneth Noland. This is a photograph that any abstract painter would envy.

A clear exposition always helps when trying to make a point, and Nicholls was set on a dandy. The afternoon shadows on the Agen canal reminded him of an ancient wisdom. Almost every culture views nature as the sum of rival twins whose many names include darkness and light, male and female, yin and yang. The Book of Genesis begins with God dividing the night from day, the firmament from the waters, and then making us in his own image: “male and female he created them.” In Chinese mythology yin represents the dark, moist female force; yang represents bright, dry masculinity.

Nicholls wrote later that he saw an underlying unity in the way the footpath curves up and connects to the sharp diagonals on the sunlit side of the bridge. Every viewer’s response will be different, though, to such an image that seems so elemental. Gauguin would approve, for he believed that “the essential in a painting is precisely that which is not expressed.” That may be, but a good hint is always a help.

John T. Spike is the director of the Florence International Biennial of Contemporary Art.