Everything about Germaine de Staël, “the most outstanding, innovative, and notorious woman writer” of post-revolutionary France, was extravagant. She was a force of nature who talked from the moment she woke up until she fell asleep. She compensated for her lack of conventional beauty with feathered turbans, brightly colored flowing gowns, and a disregard for social niceties. Enthusiasm, for Madame de Staël, was not just an emotion: It was a religion of fine sentiment and noble feelings, an appreciation of higher things, and a passionate pursuit of le bonheur. This sounds perilously close to Romantic self-indulgence, but Germaine de Staël stiffened her enthusiasm with immense intelligence, an inexhaustible relish for work, boundless generosity, and—despite fainting fits in the throes of her affaires de coeur—nerves of steel. By temperament and circumstance—her father Jacques Necker, Louis XVI’s Minister of Finance, was the wealthiest man in France—she was staunchly independent. And yet her alternately exalted and tortuous relationship with the influential writer and liberal politician Benjamin Constant, remained an indispensable part of her life long after she outgrew him.

Constant, like de Staël a Swiss citizen, would certainly never have had as illustrious a political career without her support. She lent him money to buy the land necessary for any aspirant to public office, introduced him to the most powerful men of several successive governments, settled his gambling debts, and provided him shelter in exile at her estate, Coppet, outside