Here’s an essay on what we think we know and why we shouldn’t be so sure. After I wrote it I read and enjoyed Jonah Lehrer’s piece “The Truth Wears Off: The Decline Effect and the Scientific Method” in the New Yorker, which explores similar themes. As an aside, this essay might help explain why I was a lot less inclined than many of my lefty friends to mock Donald Rumsfeld for his famous “known unknowns” remark, though I did appreciate the rendering of that remark into free verse.
In 1813, the noted ornithologist John James Audubon witnessed a phenomenon that has become legendary, both for its size and for its somber lesson: the passing of a flock of passenger pigeons. It lasted for three days and nights, stretching from one horizon to the other, darkening the sky like an eclipse. Branches and small trees broke under their weight, and many were crushed by those that landed above them. Their poop fell like snow. These flocks were “more like storm systems than assemblages of birds,” writes William Souder in Under a Wild Sky: John James Audubon and the Making of The Birds of America. They inspired a gargantuan slaughter by the farmers and recreational hunters of antebellum America, one that continued for decades until the species was nearly extinct, no longer able to sustain itself. The last one died in a zoo in 1914.