Henry David Thoreau’s Walden, published in 1854, is still so regularly taught in US high schools that US Americans usually know it by instinct. Whether or not they actually read Walden, they understand its basic plot: Thoreau went to the woods near Concord, Massachusetts “to live deliberately,” as he famously wrote. He built a tiny house by the shores of Walden Pond, in a friend’s forest. He grew beans and read books and went on walks. He laid on his belly to peer through the ice of the pond when it was frozen over during the winter. And he recorded his experiences in journals that he developed over nearly ten years into Walden. This has made Thoreau into a saint of the environmental movement, sometimes.