On the Origin of Species by Charles Darwin (1859)

Look long enough at a tangled bank, Darwin writes near the end, at the plants and the singing birds and the worms working the damp earth, and you begin to see that every one of these elaborate forms was made by laws still acting all around us. That is the quiet violence of this book: it takes the orderly, purposeful world you walked in with and hands back one that improvises, wastes, and throws up beauty no intention ever planned. The argument never bullies. Darwin stacks barnacle on pigeon on island finch on fossil shell, spends whole chapters on the objections that frightened him most, concedes what he cannot yet explain, and reasons as though you were the rigorous skeptic he most needs to convince. He had held the theory for twenty years before he dared print it, and the dread is audible in the patience. By the last page, watching life branch and complicate without end, he can call it grandeur and mean it: from so simple a beginning, endless forms most beautiful and most wonderful.