‘Shall we sit outside?” Mario Vargas Llosa asked me, gesturing through the library’s floor-to-ceiling windows at the brilliant September afternoon. The only Peruvian ever to have won a Nobel Prize, Vargas Llosa now lives in an eight-bedroom mansion on the fringes of Madrid, in the neighborhood known as Puerta de Hierro. When I arrived, a butler in a white jacket led me through the enormous two-story foyer, across gleaming black and white tiles, into a library lined with dark wood bookcases. A crystal ashtray sat next to silver dishes of chocolate and cigarettes. This imposing casona seemed like a fitting residence for the last living giant of a golden age of Latin American literature, a man who may well be the most politically important novelist of our time, but the house does not belong to Vargas Llosa. Over the library’s fireplace hung a portrait of its owner, Isabel Preysler, in a red dress.

Preysler, who was born in the Philippines but has lived in Spain since she was 16, built the home with her third husband, Spain’s former Minister of Economy and Finance Miguel Boyer, who died in 2014. Paparazzi often loiter around its gates; Preysler, 67, has been an object of fascination for Spanish-language tabloids ever since she married her first husband, the pop star Julio Iglesias, in 1971. (Her second husband was a Spanish marquis.) And it was something of a scandal that Vargas Llosa now had a desk with tidy piles of books and a bust of Honoré de Balzac in a little corner of her library amid Boyer’s old science and math books. He used to live in a floor-through apartment in the heart of historic Madrid, steps away from the Royal Theater, where the streets are as narrow as trenches. But in 2015, he left his wife of 50 years for Preysler. As I followed him out onto the terrace, I wondered briefly if part of Preysler’s appeal had been her ability to wrap him in such luxury.

We took seats under a white awning on a pair of white couches facing an aquamarine pool. My coffee arrived in a delicate pink china cup. As we talked, the sun slid behind a narrow forest of closely planted trees, which hid the street, the high stone walls and the long gravel driveway, giving the garden the illusion of a park. We talked for more than two hours in Spanish, about the Mississippi modernist William Faulkner and the Spanish superagent Carmen Balcells, about the TV shows “The Wire” and “Vikings.” For most of our conversation, Vargas Llosa was strikingly self-contained. He barely touched his glass of water and rarely moved his hands, though he said almost everything with a smile and ended many sentences with a laugh. He was like the home itself: a fortress camouflaged in the warmth of social grace. “He can strike one as being a very formal person, and he has cultivated that to some degree,” said Marie Arana, a Peruvian-American writer and former editor of The Washington Post’s books section. “People who are enormously attractive compensate by trying to be formal, to look serious.”

In March, Vargas Llosa will turn 82. He once looked like a dark-eyed John Travolta: full lips, strong chin, thick black hair. The hair is now white, but the serene manners and the prodigious self-discipline remain. He has written almost every morning of his life, publishing 59 books in 55 years, among them some of the greatest novels of the past half century: “The Time of the Hero,” “Conversation in the Cathedral,” “Aunt Julia and the Scriptwriter,” “The Feast of the Goat.” “If I didn’t write,” he told The Paris Review in 1990, “I would blow my brains out, without a shadow of a doubt.” This week Vargas Llosa has three books coming out — English translations of a novel (“The Neighborhood”) and of a collection of political essays (“Sabers and Utopias”), as well as a new volume in Spain, “The Call of the Tribe,” which is not yet available in English. It’s a condensed history of three centuries of classical liberal thought, from Adam Smith to Jean-François Revel, that doubles as a kind of intellectual autobiography.

For Vargas Llosa, writing has always been a weapon against both despair and despotism, and “The Call of the Tribe” feels like his attempt to beat back the waves of nationalism and populism now flooding our world. He is a defender of individual liberty and democracy in Latin America. His attacks on authoritarians have made him enemies among both socialists and conservatives. What he most respects in a person, he told me, is integrity: “Consistency in what you believe, what you say and what you do.” And while his insistence on saying and doing exactly what he himself believes has left a scorched path in his personal life, it has also been the making of his career.

Until he was 10, Vargas Llosa enjoyed a pampered childhood in a house filled with members of his mother’s sociable, middle-class family, which can trace its pedigree to early Spanish colonists. Grandparents, aunts and uncles looked indulgently upon his pranks — spying on women from trees, bringing his entire class home for tea. He played Tarzan with his cousins and memorized poetry with his grandfather. His father, he was told, lived in heaven. He kissed a photo of him every night before bed. In truth, Ernesto Vargas was very much alive, but he had abandoned Mario’s mother, Dora Llosa, several months before his birth. Then, in 1946, Ernesto and Dora reunited and carried Mario off to Lima.