When Montaigne developed the essay in the sixteenth century, he could not have imagined the power and longevity of his creation. "He did not set up for a philosopher, wit, orator, or moralist," wrote Hazlitt, "but he became all these by merely daring to tell us whatever passed through his mind." Ever since, writers have seized upon his example, and for over four hundred years we have encountered astonishing insights and breathtaking language by following...