Twain’s decree will be put to the test when the University of California Press publishes the first of three volumes of the 500,000-word “Autobiography of Mark Twain” in November. Twain dictated most of it to a stenographer in the four years before his death at 74 on April 21, 1910. He argued that speaking his recollections and opinions, rather than writing them down, allowed him to adopt a more natural, colloquial and frank tone, and Twain scholars who have seen the manuscript agree.

Image Mark Twain’s unexpurgated autobiography is forthcoming. Credit... Associated Press

In popular culture today, Twain is “Colonel Sanders without the chicken, the avuncular man who told stories,” Ron Powers, the author of “Mark Twain: A Life,” said in a phone interview. “He’s been scrubbed and sanitized, and his passion has been kind of forgotten in all these long decades. But here he is talking to us, without any filtering at all, and what comes through that we have lost is precisely this fierce, unceasing passion.”

Next week the British literary magazine Granta will publish an excerpt from the autobiography, called “The Farm.” In it Twain recalls childhood visits to his uncle’s Missouri farm, reflects on slavery and the slave who served as the model for Jim in “Huckleberry Finn,” and offers an almost Proustian meditation on memory and remembrance, with watermelon and maple sap in place of Proust’s madeleine.

“I can see the farm yet, with perfect clearness,” he writes. “I can see all its belongings, all its details.” Of slavery, he notes that “color and condition interposed a subtle line” between him and his black playmates, but confesses: “In my schoolboy days, I had no aversion to slavery. I was not aware there was anything wrong about it.”

Versions of the autobiography have been published before, in 1924, 1940 and 1959. But the original editor, Albert Bigelow Paine, was a stickler for propriety, cutting entire sections he thought offensive; his successors imposed a chronological cradle-to-grave narrative that Twain had specifically rejected, altered his distinctive punctuation, struck additional material they considered uninteresting and generally bowed to the desire of Twain’s daughter Clara, who died in 1962, to protect her father’s image.