Gass died at his home in St. Louis, publisher Alfred A. Knopf announced. The cause of death wasn't immediately available.
"Bill was a master writer, thinker, inspirer and human being," Gass' longtime editor, Vicki Wilson, said in a statement. "His writing was important and daring."
Along with John Barth, John Hawkes and others, Gass was among a generation of writers who opened up, and often abandoned, traditional narration. They emphasized wordplay, digression and self-conscious references to storytelling. They were praised as risk-takers who liberated the art form, and chastised for self-indulgence, makers of abstract texts best suited for college seminars.
By the 21st century, their techniques, labeled "metafiction" by Gass, were widely used by leading writers such as David Foster Wallace, Dave Eggers and Jonathan Safran Foer. Wallace would call his debut work, "Omensetter's Luck," one of the "direly underappreciated" American novels of the late 20th century, and called Gass' prose "bleak but gorgeous, like light through ice".
Gass endured as only an author can - he wrote. He won three National Book Critics Circle prizes for criticism and four Pushcart Prizes for the best work published by small presses or magazines. He published the epic novel "The Tunnel" and the acclaimed "Reading Rilke," a translation and analysis of the German poet he long revered. He was active into his 90s and in 2015 released "Eyes: Novellas and Stories."
Knopf will publish an anthology of his work, "The William Gass Reader," on June 8.
Voted into the American Academy of Arts and Letters in 1983, Gass never won a Pulitzer, but that, apparently, was for the better. The Pulitzer for fiction, he wrote in a 1985 essay, "takes dead aim at mediocrity and almost never misses; the prize is simply not given to work of the first rank, rarely even to the second; and if you believed yourself to be a writer of that eminence, you are now assured of being over the hill - not a sturdy mountain flower but a little wilted lily of the valley."
Gass managed the more secure position of faculty tenure, at Washington University (formerly known as Washington University in St. Louis). He and his second wife, Mary, lived in an ornately furnished Georgian-style house, with a vast personal library. He even earned a star on the St. Louis Walk of Fame, where he ranked, alphabetically, between former "Today" show host Dave Garroway and baseball great Bob Gibson.
Gass was born in Fargo, North Dakota, in 1924, a Depression baby whose unhappy childhood (an abusive father, an alcoholic mother) scarred him so deeply that he would later say he wrote to "get even." He was also a glutton for books who treated each text as a plate he was required to clean. Studying at Cornell University, he had his first great literary encounter, sitting in on classes taught by the philosopher Ludwig Wittgenstein.
"There was absolutely no small talk around. In fact, it annoyed him," Gass told The Associated Press in 1999. "He would take walks with a few other people and he'd whistle Mozart just to keep everybody else out of his head."
Influenced by Wittgenstein, Gass was taken by the aesthetics of language, how a word looked and sounded as opposed to what it meant. Gass was also a great admirer of Gertrude Stein, who treated plot and grammar as contrivances rather than natural components of literature.
"My stories are malevolently anti-narrative, and my essays are maliciously anti-expository," Gass once wrote. "I do not pretend to be in the possession of any secrets; I have no cause I espouse; I do not presume to reform my readers, or attempt to flatter their egos either."
Gass taught at several colleges in the 1950s and managed to publish some fiction in the literary magazine Accent. Otherwise, his manuscripts were turned down countless times and one was stolen, requiring a complete revision. Only in 1966 did his first book, the novel "Omensetter's Luck," come out.
"I couldn't even get a letter to the editor published. It was a discouraging time, I must say," he recalled.
"Omensetter's Luck" and the story collection, "In the Heart of the Heart of the Country," brought Gass widespread attention. It was a great time for mass movements, both in art and in politics, and Gass felt he belonged to an international community of rule-breaking writers.
"(Italo) Calvino was just starting to discover himself. You had all the Latino writers and Guenter Grass. Everywhere, it was fantastic," Gass said.
But the times moved on, faster than did Gass. His next full-length novel, "The Tunnel," would take more than 20 years to complete and sold little despite admiring reviews, a fate similar to shorter works of fiction such as "Willie Masters' Lonesome Wife."
Meanwhile, Gass established himself as an essayist and critic. He won book critics circle prizes for "Habitations of the Word," ''Finding a Form" and "Tests of Time." He received, most proudly, a PEN/Nabokov award for lifetime achievement, and in 2007 was the winner of the Truman Capote Award for Literary Criticism.
"I have always been interested in miracles - not just the one we are presently celebrating, but especially in the secular kinds," he said in his acceptance speech for the Capote award. "A miracle is something that cannot happen, and shouldn't, and won't again, but has occurred all the same, despite laws, odds, expectations.
"To adorn nature with a new thing: that is the miracle that matters."
Corrects to Washington University from University of Washington.
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