It’s not just Holmes’s writing that’s remarkable. It’s also the actual experience he’s describing. In this age of smartphones, it’s hard to remember a time when people actively sought out opportunities to daydream. But you can see it in just about every Atlantic article from the 19th century—our writers were in no hurry. They were enjoying the process of thinking on paper, letting their associations carry them along without worrying about where they might end up (or when they might need to use a period). Emerson wrote that way: James Russell Lowell once described the Concord sage’s prose as “a chaos full of shooting-stars, a jumble of creative forces.” But I never really understood the mindset behind this kind of writing until I read that sentence by Oliver Wendell Holmes.

To find out more, I called up David S. Reynolds, a distinguished professor at the CUNY Graduate Center who specializes in 19th century literature and history. As someone who studies that era, Reynolds chuckled affectionately at Holmes’s sentence. He said it reminded him of Herman Melville: All throughout Moby Dick and Bartleby, the Scrivener, “there are a lot of these longer sentences that go on and on, and yet they hang together and are filled with metaphors that are just wonderful.”

Reynolds pointed out that the 19th century was the Romantic age, a time when writers wanted to “luxuriate in language” and explore their inner worlds. A classic example, he said, was Walt Whitman’s 1855 “Song of Myself.” Reynolds’s students often have trouble understanding what Whitman meant when he wrote, “I lean and loafe at my ease ... observing a spear of summer grass.” “Some of them say, ‘What is this guy, a space cadet or something?’ But that’s the way Whitman was. He was able to really slow down and enjoy his environment.”

What made writers stop loafing in the grass? Mark Twain, another Atlantic contributor, had a lot to do with it. According to Reynolds, Ernest Hemingway was right when he observed, “All modern American literature comes from one book by Mark Twain called Huckleberry Finn.”

“I mean, the Holmes sentence was really designed for an educated reading public,” Reynolds said. “It doesn’t pretend to be at all vernacular. What Mark Twain did was to try and register the voices of people who weren’t necessarily educated, barely literate kids.” And Twain didn’t hide his disdain for those who wrote 200-word sentences. According to Reynolds, “He once stood up before a literary crowd at a formal banquet and went on and on about the windy, excessive language of writers like James Fenimore Cooper.”

American literature didn’t change all at once; Reynolds points out that Henry James went right on doing his thing even as Twain was writing his down-to-earth dialogue. But history was on Twain’s side. The spread of mass media, the rise of motion pictures, and the popularity of Strunk and White all helped shape the sensibilities we have now. Today’s Atlantic editors would never let some of the metaphors Holmes used into a finished story, let alone all of them in one endless sentence.

But that’s part of what makes Holmes’s writing so mischievously appealing. It breaks all our modern rules, but somehow, it works. He manages to capture the motion of the mind, the almost physical ways it floats and vibrates and whirs. Writers may write differently now, but our words and ideas still come from somewhere, and the process of bringing them to the surface is as wonderful and mysterious as it ever was. Sometimes it takes a 198-word sentence by a masterful writer to remind us of that.

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