Misfortune can cause a person unhappiness only when vice has already corrupted them, argued first-century Greek essayist Plutarch. “As a thread saws through the bone that has been soaked in ashes and vinegar, and as men bend and fashion ivory when it has been made soft and pliable by beer,” he wrote in a short piece collected in his Moralia, “so fortune, falling upon that which is of itself ill-affected and soft as the result of vice, gouges it out and injures it.”