PHYLLIS C. ROBINSON's Willa: the Life of Willa Cather is an enthusiastic, appreciative, genteel chronicle of one of Americas's greatest women writers. The author of Robinson's childhood, "who stirred my heart and kindled my imagination," Cather, as portrayed in this biography, is all "country air and earth and yellow fields of wheat . . . the fresh untroubled face of morning." Willa Cather, for Robinson, "is Nebraska."

Yet, as the Edward Steichen photograph on the book's dust jacket starkly testifies, the real Willa Cather embodies more. Robinson either fails to see or, seeing, fails to plumb the depths of the author's character. To be fair, Roninson has woven a spirited, absorbing tale. If, as a passionate reader of Cather, she occasionally gushes, her exuberance is a wholesome change from the esoterica that saddle many recent literary biographies.

In addition, Robinson has done her homework. Deftly she traces the origins of Cather's stories, points out the living prototypes of many of Cather's creations, and investigates Cather's long stints both as a drama and music critic and as a reporter for McClure's magazine. The book abounds with anecdotes about Cather's friends and associates: Dorothy Canfield Fisher, Sarah Orne Jewett, Judge McClung and his family, Elizabeth Sergeant, the family of Yehudi Menuhin, S.S. McClure, and others.

Robinson, however, seems reluctant to delve. She is almost as reticent about Cather's lesbianism as Cather herself was. Nowhere does Robinson explore Cather's long-term love relationships with Isabelle McClung and Edith Lewis, with whom Cather lived for the last 39 years of her life. Did jealousy exist between Isabelle and Edith? Did Cather, who declared that "human relations are the tragic necessity of life," herself suffer because of love? More fundamental, Robinson nowhere speculates on the motivation for Cather's homosexuality. An understanding of Cather as a woman and as a writer demands an insight into her sexual nature.

Occasionally, Robinson does jar her reader with an unexpected turn of events. Without warning, Robinson announces Cather's conversion in 1920 to Episcopalianism. Robinson's reader, who has had no hint that Cather was contemplating a conversion from the Baptist faith, is mildly annoyed. What led to Cather's change of heart? No clue is provided. Wisely Robinson has sliced her story to the bone. Her book numbers slightly more than 300 pages, rare brevity in these days of overweight biographies. But at significant moments in Cather's story the serving is perhaps too thin.

Willa Cather was plucked from western Virginia, where she was born in 1873, and transplanted to the raw Nebraska prairie at the age of 10. Though she lived in Pittsburgh, New York, and Maine, traveled extensively at home and abroad, Cather--as with so many other American writers--never left home. Her creative m,etier was the vast and lonely sky, the windswept earth of Nebraska. The land, its people, and their stories she endowed with epic dimensions: Alexandra Bergson, Antonia, Lucy Gayheart, Marian Forrester, and many others --all are rooted in the fecund soil of America's heartland. Even when she journeyed to New Mexico and Canada to research Death Comes for the Archbishop and Shadows on the Rock, Cather responded to the country with the soul of an immigrant pioneer, overwhelmed by the proud new land he is privileged to settle.

At heart, Cather was a Nebraskan. But she was more. Though Red Cloud provided Cather with a fictional microcosm, it was not world enough to keep her. Like so many of her protagonists, Cather yearned to escape from small-town life and manners. Escape, Cather later wrote, was the common denominator of her books. She read extensively. She assumed a male persona, cropped her hair, sported masculine clothes. Of the three graduates of her high school class, only Cather attended college, the University of Nebraska.

According to Dorothy Canfield Fisher, Willa "was the most brilliant student the college ever had." At times awkward and misplaced, ridiculed for her mannish dress and demeanor, Cather excelled in literature, deciding then to be a writer. In college she began to formulate her personal manifesto of art: "(Jehovah) says: 'Thou shalt have no other gods before me.' Art, science and letters cry: 'Thou shalt have no other gods at all.' "

For the next half century, Cather's life was illumined by a splendid clarity and purity of purpose. Whatever Cather did--writing music and drama criticism; editing McClure's; teaching secondary school--she was fired by an id,ee fixe: to write. "Art," Robinson explains, "was her religion and it demanded absolute devotion." Both Isabelle and Edith were devotees of Cather's altar of art, so arranging Cather's life that she possessed the peace and privacy in which to create.

No Amy Lowell, Cather eschewed notoriety, never flaunted her lesbianism. The successes of My Antonia and Death Comes for the Archbishop, the Pulitzer Prize awarded for One of Ours, the Howells Medal, and the many other honors heaped upon Cather did not distract her from the primary purpose of her existence: writing. "Genius," Cather once commented, "means relentless labor and passionate excitement from the hour one is born until the hour one dies." Cather worked with the intensity of a laborer on a farm about to fold: from 1912 to 1927, along with numerous articles and short stories, she produced 11 books.

"The world," Cather once observed, "broke in two in 1922 or thereabouts." As she aged, life darkened. Friends and family began to die. After finishing a handwritten copy of Lucy Gayheart (1935), Cather strained the tendons of her right hand. The pain became excruciating, and before long she could barely hold a pen. Only with difficulty could she sign her name. This disability, which lasted until her death, was nightmarish: for an author who had to see the words form on the page, the suffering was unbearable, and the effects on Cather's psyche disastrous. Then in 1938, beloved Isabelle died; from this death, Robinson writes, Cather never fully recovered. Production slackened, and Cather lived her last years "in almost constant pain." Robinson notes: "After one is forty-five, she said, it simply rains death all about one and after fifty the storm grows fiercer." Cather herself succumbed to the storm, dying in 1947, in New York, at 73.

On Willa Cather's gravestone these words from My Antonia are carved: " . . . that is happiness: to be dissolved into something complete and great." Cather spent her life striving to create a complete and great art. Thea's plea in The Song of the Lark is Cather's also: "Living's too much trouble unless one can get something big out of it . . . I only want impossible things. The others don't interest me." Though this biography has its flaws, Robinson does capture some of the fierce magnificence, the bigness, the epic stature of Willa Cather, who made Nebraska a metaphor for the world.