Visual art has long played an important role in the novels of Ali Smith, 58, one of Britain’s leading writers and a four-time Booker Prize finalist. Her 2014 novel “How to Be Both” is jointly narrated by the 15th-century Italian artist Francesco Del Cossa and a British teenager in the 21st century, who becomes obsessed with one of his paintings in London’s National Gallery. She has collaborated on projects with her longtime partner Sarah Wood, an artist, curator and filmmaker.

But when Ms. Smith began her tetralogy of novels named after the seasons—whose final installment, “Summer,” was published in the U.S. last month—she didn’t know how important art and artists would become. In the four years covered by the books, a large cast of characters—among them a centenarian songwriter, a young art lecturer, a nature blogger, a brilliant near-juvenile-delinquent and a movie director—fall in and out of love, form de facto families and debate the political issues of the day, particularly immigration and Brexit. In each volume, fictional characters mingle with real-life artists, who play significant roles in the plot.

For Ms. Smith, ‘Art...will always shake us out of ourselves and into new, renewed selves.’

For Ms. Smith, ‘Art…will always shake us out of ourselves and into new, renewed selves.’

Photo: Leonardo Cendamo/Getty Images

In 2015, when she was planning the first volume, “Autumn,” Ms. Smith happened to see a magazine reproduction of “Colour Her Gone,” a 1962 picture by the British Pop artist Pauline Boty. The painting is divided into three vertical sections: In the middle Boty depicts Marilyn Monroe at her most seductive, surrounded by flowers, while the flanking panels feature austere, abstract designs. The disconcerting effect is heightened by the way the Monroe panel is placed off center.

Boty, who died in 1966 at the age of just 28, struggled to be taken seriously as a female Pop artist. Her work addressed social and political issues head on, just as Ms. Smith does in “Autumn,” which she was writing at the height of the U.K.’s Brexit debate. Ms. Smith decided to make Boty a character in the novel, giving the artist a monologue-like chapter to herself. “A great many men don’t understand a woman full of joy, even more don’t understand paintings full of joy by a woman,” the character says. “Boty’s spirit—it’s the spine of that book,” Ms. Smith says now. “I’m thankful for it.”

Each volume in the series features a different 20th-century British artist, though in different ways. The second book, “Winter,” discusses the sculptor Barbara Hepworth, whose pierced stone abstract sculptures recall the work of Henry Moore. Ms. Smith says that Hepworth “knows how the physical universe and the human world come together and come apart.” In “Spring,” has-been director Richard Lease is inspired by the contemporary artist Tacita Dean, especially her 2017 work “The Montafon Letter,” an enormous picture of a mountain and avalanche: “As he stood there, what he was looking at stopped being chalk on slate, stopped being a picture of mountain. It became something terrible, seen,” Ms. Smith writes.

‘Merzbild 1A: The Psychiatrist,’ a 1919 collage by Kurt Schwitters, who is a character in Ms. Smith’s novel ‘Summer.’

‘Merzbild 1A: The Psychiatrist,’ a 1919 collage by Kurt Schwitters, who is a character in Ms. Smith’s novel ‘Summer.’

Photo: Alamy

Finally, in “Summer,” Ms. Smith introduces two German artists who fled Nazism and took refuge in the U.K.: Fred Uhlman, known for his vivid landscapes and surrealistic drawings, and Kurt Schwitters, best known for his collages. In 2020, the 104-year-old Daniel, one of Ms. Smith’s fictional characters, recalls being interned as an enemy alien on the Isle of Man during World War II alongside the two artists.

Daniel recounts that Uhlman spent his time making drawings in which a little girl with a balloon moves unscathed through wartime horrors: piles of skulls, ruined buildings, hangings. In real life, children were on Uhlman’s mind at the time: The internment had prevented him from finding out any information about his pregnant wife. After the war, Uhlman published 24 of these drawings under the title “Captivity” (1946).

The antic Schwitters, by contrast, barks like a dog, sleeps in a basket and, for lack of better material, makes sculptures out of porridge that then molder and turn green. “These sculptures are alive…there is no higher accolade,” Daniel diplomatically assures Schwitters. In real life, Schwitters left the camp in 1941 for London, where he met with little success, though his work was later recognized as a forerunner of Pop art.

For Ms. Smith, the purpose of making art and artists so central to these novels is that the arts “ask response. They ask for our thinking, feeling presence. The visual arts do it with an immediacy we think we’re used to…but we’re never used to art, which will always shake us out of ourselves and into new, renewed selves.”