Thoreau rendered Walden in a precise and naturalistic style. He composed many long, flowing, detailed sentences that give the text a sense of grandeur. Sometimes he follows up a long sentence with a short, pithy aphorism, especially in the chapter "Higher Laws":
Fishermen, hunters, woodchoppers, and others, spending their lives in the fields and woods, in a peculiar sense a part of Nature themselves, are often in a more favorable mood for observing her, in the intervals of their pursuits, than philosophers or poets even, who approach her with expectation. She is not afraid to exhibit herself to them.
Here, a short statement—"she [Nature] is not afraid to exhibit herself to them"—concludes a grand list of people who spend time in Nature. Many commas appear in the complex compound sentence, but none appear in the simple sentence (which has an easily-identifiable subject and predicate). This grammatical contrast conveys the comparative simplicity of Nature to the unnecessarily complicated lives of men in the modern world.
Another important element of the style is Thoreau's imaginative precision. He always goes to great lengths to convey the beauty of nature. Whether he writes of "the usnea lichen [that] hangs in festoons from the white-spruce trees" or the "quite dazzling and transcendent beauty" of pickerel fishes, he makes sure to lavish attention on the smallest, most unassuming details about life on the pond. One might not usually find lichen or fish beautiful, but the details make each scene quite convincing. Throughout Walden, a precise naturalistic style helps Thoreau convey the complexity of human life and the beautiful simplicity of nature.