“The central theme of Anna Karenina," he said, "is that a rural life of moral simplicity, despite its monotony, is the preferable personal narrative to a daring life of impulsive passion, which only leads to tragedy."

"That is a very long theme," the scout said.

"It's a very long book," Klaus replied.

[...]

"Or maybe a daring life of impulsive passion leads to something else," the scout said, and in some cases this mysterious person was right. A daring life of impulsive passion is an expression which refers to people who follow what is in their hearts, and like people who prefer to follow their head, or follow a mysterious man in a dark blue raincoat, people who lead a daring life of impulsive passion end up doing all sorts of things.”