About my eleventh grade English class, I remember very little, and none of it very pleasant. Miss Elizabeth Kapp, a stern maiden lady of some years, led us to believe that American literature pretty much stopped at the 19th century (and so, some of us were convinced, did she: who else would have kept portraits of Robert E. Lee and Stonewall Jackson hanging on the walls of the classroom, and this in a completely integrated school?).

Not only that, but the 19th century literature she championed ran to oozy poets like James Greenleaf Whittier, William Cullen Bryant, and Sidney Lanier, all of whom we were made to memorize by the yard and then recite aloud. The one poem she reserved for herself was Poe’s “The Bells,” and even now I can see the wattles of her chin shake as she declaimed “the tintinnabulation of the bells, bells, bells.”

Miss Kapp was more hagiographer than critic. The writers we studied were all, she led us to believe, beyond reproach. But there was one exception. She openly mocked Henry David Thoreau, whose bicentennial we celebrated July 11.

“You know,” she confided with a cynical chuckle one day while frog marching us through Walden, “he may have gone out and lived by himself for a couple of years, but he was mighty happy to go home to Mama’s in town for a chicken dinner every Sunday.”

Her snide aside confused me twice over, once because it was out of character for Miss Kapp to malign an author, and again because, as an apprentice hippie, I’d read Walden on my own a year before and found nothing to complain about. I loved his back-to-the-land preachments and his categorical condemnation of the mindlessly acquisitive bourgeois life. Reading Thoreau was like listening to a sympathetic, companionable friend who had it all figured out.

It did not occur to me for many years that Miss Kapp, not being a child of the age of Aquarius, might see Walden a little differently, that she might in fact take it for what it was—a fierce indictment of her easy, middle-class life. So maybe she went looking for weak spots, holes in the fabric of Thoreau’s prose where she could pull a thread and unravel the sense he was making. And what better way to do that than by questioning his accomplishment.

He wasn’t really self-sufficient. He wasn’t really an ascetic hermit finding himself by a pond. No, he was a fraud, and a lazy fraud at that, a man who spent his life telling other people what to do. To hear her tell it, he might as well have stolen pies off kitchen windowsills like some passing hobo.

I forgot all about this for years, until recently, when I found that you need not be a card-carrying member of the United Daughters of the Confederacy to loathe the transcendental, abolitionist bard of Walden Pond. Millennials of my acquaintance, it turns out, also think he was a fraud who preached what he did not practice.

This took me longer to unriddle, until it occurred to me that Thoreau himself is never cynical. Worse, he is earnest, a quality that doesn’t resonate with many people under the age of 70, since the last half century is nothing if not the golden age of cynicism. We just assume that every hero these days comes factory equipped with feet of clay. Trust no one over 30, my generation said. How quaint. Trust no one, say those who came after us.

Then, when I began reading Laura Dassow Walls’ wonderful new biography of Thoreau, I found that the problem is even bigger and has far deeper roots than I first expected. It turns out that tagging him as a hypocrite was fashionable even before he published Walden in 1855—for years after a young Thoreau and a friend accidentally set some woods on fire near Concord, “some would taunt him by hiding and shouting ‘Burnt Woods’ at his back,” according to Walls. This is what you get for being the town gadfly.

Mocking the man, it turns out, has always been the easiest way to inoculate against the often hard lessons he has to teach. As Walls puts it, “all those harmless and loving dinners at home, where he dropped off his laundry, caught up on the news, packed in a good meal, and maybe carried away a pie for breakfast laid him open to endless charges of hypocrisy. No other male American writer has been so discredited for enjoying a meal with loved ones or for not doing his own laundry. But from the very beginning, such charges have been used to silence Thoreau.”

Thoreau may have been a first-class eccentric, by the standards of his time or any other, but he never pretended to be anything he wasn’t. As Mohandas Gandhi said of him, “he taught nothing he was not prepared to practice in himself.” Indeed, he was downright discreet when it came to flaunting what he knew, because when it came to the natural world, he was a walking encyclopedia. It was to Thoreau that the farmers and woodsmen of Concord turned when there was a question about flora and fauna. He was downright oracular, on the page and in person.

There was surely more than a little self-consciousness in Thoreau’s decision to spend two years by Walden Pond. He was after all, a writer whose principal subject was himself. Walls even calls the move a piece of performance art. But that does not negate his sincerity. Indeed, what he was trying to do was first simplify his life—get it right down to the chassis—and then forge the essentials into one harmonious whole. As Walls says, moving to Walden was a declaration that from then on “Thoreau would be a writer in an entirely new sense: instead of living a little, then writing about it, his life would be one single, integrated act of composition.”

Even before the Walden experiment, which he embarked on at the age of 28 in 1845, Thoreau strove to unify the separate parts of his life, so that writer and naturalist, day laborer and loafer, son and citizen all chimed together and informed each other. He wanted a life that adhered around core principles and could not be pulled apart. In some ways he willed this into being, but in other, more important ways, he was just acknowledging who he was. Nowhere was this plainer than in the marriage of his two favorite activities: writing and walking (a ten-mile walk was nothing to him). Walls says that even before he moved to Walden Pond, he was rhyming the rhythms of the walker and the writer such that they became inseparable for him: “Walking was becoming synonymous with writing, the measure of his steps with the measure of his prose.”

In one sense, Thoreau was too good at his job: Much of the wisdom in Walden seems self-evident to us. But that is only because we have so completely absorbed what Thoreau tried to teach us. Those who today take environmentalism, vegetarianism, Native American rights, civil disobedience, and pacifism for granted forget or simply don’t know that it was Thoreau who first introduced American readers to these concepts. Without question he was the godfather of the environmental movement, and he singlehandedly pioneered that admixture of science writing, memoir, op ed, and reporting that we call contemporary nature writing.

Beyond that, I would urge anyone who encountered Thoreau in high school or college and abandoned him there to go back for another look. Sentences such as “The mass of men lead lives of quiet desperation” sound complacently self evident when you're 16 or 20. Try it again when you’re 10 or 20 years older, and that line takes on an almost Beckett-like caste.

I can’t say enough good things about Walls’ book. It is almost certainly what its publisher promises: the Thoreau biography that will be read for generations. But beyond that, it’s simply one of the best biographies I’ve ever read, beautifully researched and written, and sympathetic but never apologist. Even if you come to her book as someone who likes the Thoreau met in his writing, her portrait makes you like him even more.

He was one of those people who are happiest outside. His keen attention and bottomless curiosity made him an extraordinary naturalist—and not just as an avid collector in the field: he knew the science, too. He was one of the first Americans to read Darwin’s On the Origin of Species and probably the first to grasp how profoundly it game-changed natural science.

Such intense, omnivorous curiosity about the workings of the world might be Thoreau’s defining characteristic—it certainly would be in a less faceted, less contradictory man. Because for all his nature loving, he also loved tools and machines and gadgets. Carpenter, house painter, boatwright, arborist—he truly was as close to self-sufficient as anyone could be in 19th century America. He was Concord’s handyman—the ideal handyman in what might be considered America’s ideal town, since Thoreau’s clients for home repair and gardening included Emerson, Hawthorne, and the Alcotts. He may have been a home boy nearly his whole life, but what a home. He was also the town’s chief surveyor—his principal livelihood. And he spent nearly his whole life, in one capacity or another, helping out in his family’s pencil factory—his refinements with graphite made Thoreau pencils the most popular in the U.S.

All this I learned from Walls, who is as good at the small stuff as she is on the big picture. From her I learned that Thoreau almost never saw a deer, the ecological depredations of the English settlers being so severe that entire animal populations were eradicated by the time he was born. Further, “summerhouses, writer’s shanties, and wilderness retreats” like the one Thoreau built for himself at Walden were all the rage among young 19th century Americans eager to find themselves in nature. And thanks to Walls, I now know that those weird under-the-chin beards that you see on 19th century men were not just some odd fashion statement: Called “Galway whiskers,” they were worn by consumptives like Thoreau, who thought they protected the neck and warded off tuberculosis.

In the end, of course, Thoreau survives on the strength of his own writing or not at all. Since he’s made it this far with his reputation more or less intact--he weathered the charges of hypocrisy in his own lifetime, and so he has in death—I’d say the chances that he’ll survive are more than fair. Certainly what he has to tell us has not dated at all. Indeed, if I had a million dollars to spare, I’d send a copy of Walden to every Trump appointee at the Environmental Protection Agency.

Thoreau has been dead for more than 150 years. Miss Kapp has, I can only assume, long since departed for that great teacher’s lounge in the sky. I am no longer a hippie, apprentice or otherwise. But I’m still reading Walden, and I discover something new every time I open it. It remains a living testament that never stales.