Charismatic, brilliant, and beautiful, the American writer Natalie Clifford Barney, who lived in Paris for most of her long life, is best known for three things: her Left Bank literary salon, often acknowledged as the most important of the twentieth century; her books of epigrams about life, love, and the nature of womanhood; and a liberated approach to sex that she refused to cloak, even in the midst of the Victorian era. Born to great wealth in...