“Lake Nemi,” 1872, features a lone, sunlit monk surveying the lake from a small hill. Eliminating most structures and trees, Inness achieved a unified, harmonious composition. Courtesy Museum of Fine Arts, Boston.

A photograph of George Inness, circa 1890. Courtesy Archives of American Art.

George Inness (1825-1894) is surely one of the most significant figures in American art history, but he is often overlooked in discussions about major American painters. Regarded by some as the father of American landscape painting, even the finest of our landscapists, he is nonetheless sometimes slighted by chroniclers of our art. Robert Hughes, for example, in his massive and generally admirable overview, American Visions: The Epic History of Art in America, 1997, makes only one, passing reference to Inness.

Because in recent years there have been few large exhibitions of his work, opportunities to appreciate Inness anew and evaluate his body of work have been few and far between. The splendid show, “George Inness and the Visionary Landscape,” on view at the venerable National Academy of Design through December 28, features some 40 paintings. It should go a long way toward reclaiming Inness’s central role in the development of Nineteenth Century landscape painting in this country.

The exhibition is curated by Adrienne Baxter Bell, a PhD candidate at Columbia University. When finished at the National Academy, it travels to the San Diego Museum of Art, January 24-April 18. The accompanying catalog, written by Bell, is scholarly and enlightening.

Bell explores at some length the influence of the doctrines of Swedish mystic Emanuel Swedenborg and the ideas of philosopher William James on Inness’s art. “[F]or every hour that Inness spent painting,” she observes, “he seems to have spent another hour harvesting metaphysical problems and ideas from the domains of philosophy, psychology, mathematics, and especially theology.”

Born in Newburgh, N.Y., Inness was the son of a successful merchant who wanted him to go into business, but young George had his mind set on becoming an artist. He spent time in New Jersey and Massachusetts, apprenticed for a short time with an engraver, and studied briefly with French artist Regis Gignoux in New York City. He was largely self-taught.

Inness was clearly aware from the start of the work of Thomas Cole and the Hudson River School and was greatly influenced by several sojourns in Europe.

He lived off and on in Manhattan, although in 1865-67 he taught art at a social reform community, “Eagleswood,” in Perth Amboy, N.J. Inness settled permanently in Montclair, N.J., in 1885, with winters in Tarpon Springs, Fla., in the 1890s.

His career can be divided into two major areas. In the early period, through the 1860s, he adapted the style of Hudson River School painters to his own impulses, aligning it with European landscape traditions. His late style, evolved after his return from Europe in 1875, is characterized by the poetic, atmospheric landscapes for which he is best known.

Inness’s first trip to Italy, 1851-52, led to “A Bit of the Roman Aqueduct,” 1852, a pastoral scene composed along the lines of French painter Claude Lorrain and Hudson River School artists. Trees frame shepherds and cattle around a foreground pool, with the aqueduct in the middle distance and mountains beyond in this first canvas in the exhibition. It is a facile, conventional image of its time.

Exposure to the work of the Barbizon School, during a stay in France, 1853-54, prompted works that owe much to the inspiration of Jean-Baptiste-Camille Corot and Theodore Rousseau. Inness’s affinity for their subtle interpretations of nature’s mysteries is reflected in the expressive brushwork, tonal harmonies and careful delineation of light and shadow in such rural scenes as “Hackensack Meadows, Sunset,” 1859, and “Landscape,” 1860. The latter was the artist’s diploma picture for the National Academy of Design, where he had first exhibited in 1844.

In “The Huntsman,” 1859, replicating a sylvan setting that reminds one of Hudson River stalwart Asher B. Durand, the figures of the hunter and his prey blend into the foreground. The viewer’s eye is drawn to the vibrant play of light and shade deep into the forest. “Evening Landscape,” 1862, is a large, glowing canvas in which the warm tones of a sunset give the setting an “ethereal quality,” as Bell puts it.

According to Bell, Inness falls within the “visionary tradition in American history,” since he cast his art in mystical, spiritual terms, specifically inspired by scientist-turned-visionary Swedenborg (1688-1772). After achieving much as a scientist and inventor in Sweden, Swedenborg experienced a series of epiphanies that led him to write about his visionary ideas.

His theories revolved around the conviction that there is a direct correspondence between the spiritual and natural worlds. The presence of the divine in nature was an honored tradition among American landscapes and Inness sought to continue it through compositional structures that evoked spiritual aspects in nature.

“A Winter Sky,” 1866, offers a hazy, evocative rendering of the reflection of the setting sun on a frozen pond ringed by clumps of trees and vaguely visible houses. This highly personalized image, conveying a sense of well-being and contemplation, is likely to “awaken an emotion in viewers,” as the artist sought. “Inspired, in all likelihood, by his prolific reading of Swedenborgian literature during the 1860s, Inness captured, in this quietly impressive painting, the fundamentally and profoundly enigmatic character of the religious experience,” writes Ball.

On a third visit to Europe, to Italy from 1870 to 1874, Inness became interested in composing paintings based on geometric shapes and mathematical principles. He injected a heightened sense of order and arrangement into his landscapes. “Lake Nemi,” 1872, for example, features a lone, sunlit mink surveying the lake from a small hill. Eliminating most structures and trees, Inness achieved a unified, harmonious composition.

The dark and romantic “The Monk,” 1873, probably set on the grounds of a villa near Albano, is described by Bell as one of the artist’s “most haunting works and among the finest paintings of the Nineteenth Century.” In this large — 389/16 – by 641/8 -inch — canvas, a solitary, hooded monk strolls around a walled garden, over which loom tall, slender Italian pine trees silhouetted against a dramatic yellow sky.

In the spare and refined but vividly hued “Castel Gondolfo,” 1876, the walled papal palace on the right presides over an expanse of Lake Albano in a composition filled with geometric divisions of space. Expressing Inness’s sense of solidity, stability and harmony when he viewed the scene, this work captures, says Bell, “his desire to create a new pictorial expression of nature’s divine order.”

In the late 1870s, commenting on the purposes of art, Inness said, “A work of art does not appeal to the intellect. It does not appeal to the moral sense. Its aim is not to instruct, not to edify, but to awaken an emotion.”

During the late 1870s and 1880s, Inness shaped his landscapes around the expressive use of vigorous brushstrokes. His bravura technique enhanced his sense of nature’s restless agitation in such masterpieces as “The Coming Storm,” 1878. Here, dark gray storm clouds glower over pastureland ringed with wind-swept trees. It captures the instant before the storm blots out the sunny countryside.

Discussing the intricacies of Inness’s brushwork in this canvas, Bell says, “The range and variety of Inness’s brushstrokes, and the uncanny precision with which he uses them, persuasively embody the dynamism and unpredictability of oncoming storms.” It illustrates how the artist used technical means to convey narrative, moods and sensations in a vignette of turbulent nature.

In “Hazy Morning, Montclair,” 1893, bravura brushwork helps convey the painter’s emotional response to a scene close to home.

By all accounts, Inness was an impetuous, intense painter who attacked his canvases with energy, enthusiasm and intuition. Working swiftly, he mixed his colors as he proceeded, often changing course as a painting developed on his easel. On occasion he used his fingers to apply pigment. “[P]ainting for Inness,” writes Bell, “appears to have been, in equal parts, a physical, psychological, and spiritual activity.”

Bell examines ways in which Inness’s visionary paintings of the 1870s and beyond reflected his interest in Harvard psychologist-philosopher James’s theories of consciousness as a “stream of thought” or a “stream of subjective life.”

According to curator Bell, among Inness’s later works showing a marked Swedenborgian influence are two especially lovely landscapes, “Sunset Glow,” 1883, and “Landscape,” 1888. In the former, an atmospheric setting sun bathes the field and trees in an ethereal glow that barely reveals the figures of a man and his dog in the middle ground. “Tethered loosely to the familiar, ‘Sunset Glow’ seems to peer across an imaginary threshold into a new metaphysical realm, one that reflects Inness’s Swedenborgian interpretation of nature as the domain of ‘appearances,'” observes Bell.

Inness’s late efforts to capture the effects of transient light in intimate, poetic reveries are reminiscent of Corot’s silvery woodland idylls and Whistler’s nocturnes. “Landscape,” painted six years before his death, is a relatively small work. It conveys reflections of sunlight on trees and foliage in a symphony of harmonious colors that show Inness at his lyrical best.

“Summer, Montclair (New Jersey Landscape),” 1891, is characterized by softened forms, subtle tonalities and an overall feeling of serenity and mystery. The vaporous arrangements of forms and harmonies of air, color, light and pigment make Inness’s concluding works especially memorable.

Two of his culminating works, “Hazy Morning, Montclair” and “The Home of the Heron,” both 1893, are autobiographical in the sense that they reflect the artist’s familiarity with the land around his New Jersey home and the area in Florida where he spent winters. Each offers an affectionate, subdued, atmospheric glimpse into a tranquil setting. They “embody many of the enigmas of Inness’s search for the elusive ‘moving spirit’ that inspired much of his artistic work, indeed, much of his life,” says Bell.

Inness’s high standing toward the end of his life is documented by the fact that at the World’s Columbian Exposition of 1893 in Chicago, the 68-year-old artist exhibited no fewer than 15 paintings in the American display.

In ill health toward the end, Inness nonetheless traveled widely in this country, to Florida, Georgia, Louisiana and California in the 1890s, for instance. On his final trip to Europe, he visited Paris, Munich and Baden Baden before dying, while viewing a sunset, at a hotel in Scotland in the summer of 1894.

The exhibition and catalog offer visual evidence and textual documentation to show that, as Bell puts it, the infusion of theological/metaphysical ideas into Inness’s late paintings “encourage viewers to think in new ways about themselves and about their relationship to nature and to the divine. Seen as a group, they remain some of the most thought-provoking and inspiring works in the history of art. Their authority and the mystery of their effectiveness remain as powerful today as they did more than a century ago.”

The first major Inness show in almost two decades, this exhibition and its catalog are especially valuable because they explore how the artist’s devotion to Swedenborgian concepts, along with his personal search for fresh ways to interpret nature, led to the creation of a new form of visionary landscape. Inness’s commitment to breaking away from the conventions of his contemporaries, fueled by studies in psychology and philosophy, make him a unique, pioneering force in Nineteenth Century American art.

This exemplary exhibition, showcasing the enduring quality of his oeuvre, should solidify Inness’s high standing in the annals of our art. A gifted technician spurred by big, new ideas, George Inness presaged some of the important facets of modernism that continue to inspire contemporary painters.

The well-illustrated, 174-page catalog features a comprehensive, scholarly essay and entries about individual works by guest curator Bell. Some of the text will be a bit hard going for laymen, but it does offer in-depth examinations of the thinking of Swedenborg and James that so influenced Inness and others of his time. Published by the National Academy and George Braziller, Inc, it is a bargain at $19.95 (soft cover).

The National Academy of Design is at 1083 Fifth Avenue at 89th Street. For information, 212-369-4880.