“No writer would ever betray his secret life,” the novelist Patricia Highsmith wrote to a friend in 1940. “It would be like standing naked in public.”

More than 20 years after her death, Highsmith’s secret life — her reflections on her creative aspirations, her tumultuous romantic relationships and her fascination with the psychological underpinnings of violence — will be made public for the first time, as her estate prepares to publish hundreds of pages from her personal diaries.

The diaries, which Liveright Publishing plans to release in the United States in 2021 as a single book, offer a glimpse into the life of a literary figure whose sharply observed psychological thrillers, including “Strangers on a Train” and “The Talented Mr. Ripley,” became cultural touchstones. She was a secretive, often prickly woman who remained a cipher even to her friends and lovers, and a trailblazer who wrote one of the first mainstream novels depicting two women in love. But she could be blinded by her own bigotry and espoused racist and anti-Semitic views .

Scholars have long known about the diary entries, but they have not previously been available to the public. Spanning nearly 60 years, the entries reveal new facets of Highsmith’s life. They catalog her thoughts on such subjects as good and evil, loneliness and intimacy, and love and murder, which she saw as intertwined: “Murder is a kind of making love, a kind of possessing,” she wrote in 1950.