When Anna and Vronsky return to Petersburg, Anna is ostracized by society—that is, until she officially divorces Karenin. Princess Betsy visits Anna despite the social repercussions and uses a metaphorical idiom to explain herself:
And, indeed, she went to see Anna that same day; but her tone was now quite unlike what it used to be. She was obviously proud of her courage and wished Anna to appreciate the faithfulness of her friendship. She stayed less than ten minutes, talking about society news, and as she was leaving said:
‘You haven’t told me when the divorce will be. Granted I’ve thrown my bonnet over the mills, but other starched collars will blow cold on you until you get married. And it’s so simple now. Ça se fait. So you leave on Friday? A pity we won’t see more of each other.’
The idiom "I've thrown my bonnet over the mills" is a direct translation from a French idiom, which means to throw caution to the wind. In this passage, Betsy throws caution to the wind by going to see Anna, even though she has been ostracized by society and visiting her is seen as improper. Betsy uses the French idiom to explain how she has given up caring what society thinks—or, more accurately, to illustrate the fact that she refuses to conform to the rules of society. The idiom compares “bonnet” to one’s caution and adherence; throwing the bonnet over the mills, therefore, means to abandon caution. The people in society who do not think for themselves, judge others based on their actions, and then treat them with disdain are the “starched collars” of which Betsy speaks. Through this idiom, Betsy demonstrates the influence of society and its carefully carved rules on behavior.