In 1839, fifteen years before he embarked on an experiment to live deliberately, Henry David Thoreau (July 12, 1817 – May 6, 1862) set out with his brother John to drift and row at leisure up two rivers in northern Massachusetts.

Gradually the village murmur subsided, and we seemed to be embarked on the placid current of our dreams, floating from past to future as silently as one awakes to fresh morning or evening thoughts.

Although the trip with his brother occurred in 1839, Thoreau wrote A Week on the Concord and Merrimack Rivers while living at Walden Pond. The account is subsequently immediate and somewhat removed, which allows Thoreau ample space to observe and philosophize.

By noon, we were let down into the Merrimack through the locks at Middlesex, just above Pawtucket Falls, by a serene and liberal-minded man who came quietly from his book... With him we had a just and equal encounter of the eyes as between two honest men. The movements of the eyes express the perpetual and unconscious courtesy of the parties.

In this deeply reflective writing, Thoreau considers religion, humanity, government, and wilderness. He tries to make sense of the disruptive Industrial Revolution.   On the other side of the Atlantic, British poet John Clare was writing on the same subject. Where Thoreau spoke about the changes to society and culture, Clare wrote poetry focused on the landscape itself and how it was being divided and sectioned into railways and farms.

 River Arun, Sussex.

We often imagine Thoreau as an anti-society advocate, but that is a modern imposition. As most of society ceases to earn a living from the land, we've begun to see nature as something we enter or exit, not something we coexist with.   Read more from Sylvain Tesson's retreat to Siberia, for example, or Robert Macfarlane's search for remaining wildness in our human-forged landscape.

Thoreau—like his contemporary Ralph Waldo Emerson and Rachel Carson, who wrote Silent Spring a century later—was interested in the threshold of nature, the point at which humans interact—hiking, fishing, hunting, etc.—and how to keep that interaction balanced and sustainable.

Life on earth has been a history of interaction between living things and their surroundings. To a large extent, the environment has molded the physical form and habits of the earth’s vegetation and animal life. […] Only within the moment of time represented by the present century has one species—man—acquired significant power to alter the nature of his world.
From Rachel Carson's Silent Spring

Thoreau went into nature, indeed, but he wasn't a hermit. Thoreau was known to be social at Walden (though he tired of company), and even his sojourn along the Merrimack is primarily focused on people and their societal constructions.   I'm collecting people who retreat to nature in a more complete way, giving themselves over to it entirely, such as Sylvain Tesson, who spent six months alone in Siberia, or Annie Dillard, whose sojourn at Tinker Creek is exceptional and solitary. Poet Mary Oliver spoke for everyone of this ilk when she said 'Life comes at me with its busyness."

The small houses, which were scattered along the river at intervals of a mile or more, were commonly out of sight to us, but sometimes when we rowed near the shore, we heard the peevish note of a hen or some slight domestic sound which betrayed them. [...] These humble dwellings, homely and sincere, in which a hearth was still the essential part, were more pleasing to our eyes than palaces or castles would have been.

Humility and austerity were critical features of the Transcendental movement—aspects often overlooked in favor of the more splashy environmental elements.

Transcendentalists believe humans can figuratively transcend our daily lives and habits to a higher emotional and intellectual atmosphere, into something outside our existence. Thoreau called it a great "Something." Many words have been used for this (a few are gathered in A Singular Focus on the Eternal). Nature was a primary catalyst for such transcendence.

Thoreau varies his pace and view -moving deftly from the infinite to the immediate.   Moving between the temporal and the infinite, the concrete and the imagined, is a gift of so many writers and poets and something best afforded us by nature.  
Read more from American poets Mary Oliver and Wendell Berry, who, like Thoreau, used nature as their primary text. Or Penelope Lively, who found erudite inspiration from musings on gardening. Nature wraps us in thought. I particularly liked a passage where he gazes upon those who came before.

It is a wild and antiquated looking grave-yard, overgrown with bushes, on the high road, about a quarter of a mile from and overlooking the Merrimack, with deserted mill stream bounding it on one side, where lie the earthly remains of the ancient inhabitants of Dunstable.

[…]

You read the names of Lovewell, Farwell, and many others whose families were distinguished in Indian warfare. We noticed there two large masses of granite more than a foot thick and rudely squared, lying flat on the ground over the remains of the first pastor and his wife. It is remarkable that the dead lie everywhere under stones.

The River Arun, Sussex. “Lone manhood's cares, yet waking fondest sighs: Ah! that once more I were a careless child!” wrote Samuel Taylor Coleridge.

Both Thoreau and Emerson are buried in Concord, Massachusetts, marked by well-visited stones. Will they always be remembered? Thoreau noted, "I have seen how the foundations of the world are laid, and I have not the least doubt that it will stand a good while." Now that he's part of the foundation, I can't help but agree.

I turn to Emerson and Thoreau frequently for insight and comfort. A Week on the Concord and Merrimack Rivers, especially. How would these men react to today's world? The belief that man's dignity was rooted in his associations with nature was a core value of the U.S. Founding Fathers and 19th-century Transcendentalism.

 Henry David Thoreau, 1856.

If Thoreau were alive today, the loss of that association—that people can exist without connection or care for nature—would sadden him most.

Accompany Thoreau's atmospheric journey with a read of Wendell Berry's case for our harmony with nature, Steinbeck's road trip of self-discovery in America, and George Borrow's perambulatory observations of Wales written a few years after Thoreau's River, bringing the same wide-eyed and openhearted curiosity to his countrymen.