I know positively—yes, Rieux, I can say I know the world inside out, as you may see—that each of us has the plague within him; no one, no one on earth is free from it. And I know, too, that we must keep endless watch on ourselves lest in a careless moment we breathe in somebody’s face and fasten the infection on him. What’s natural is the microbe. All the rest—health, integrity, purity (if you like)—is a product of the human will, of a vigilance that must never falter.
