Placid, virtuous, and all but mute, Madame Arnoux is less a woman than an object onto which Frédéric projects his desires. From the moment Frédéric sees her on the ship he is taking to Nogent, Madame Arnoux occupies his imagination as a specimen of superb beauty and female perfection. Often portrayed as sitting by a fire, sewing, and tending to her children, Madame Arnoux is a pure, ideal mother figure. This idealized image is so intense in Frédéric’s mind that he rarely speaks of lust when he speaks of his desire for her. He says at one point that he can’t think of her naked. Although she is virtuous, she does eventually reciprocate Frédéric’s feelings, even though they do no more than share a kiss. Frédéric engages liberally in sordid sexual affairs, particularly with the well-known Rosanette, yet none of these women satisfy him as he believes Madame Arnoux would. She is the sole object of his affection, his impossible dream.
Madame Arnoux’s role in Frédéric’s life is ultimately one of a mother rather than a mistress. He can never possess her sexually, but she is a constant force in his life, both in reality and in imagination. She is the one thing that stays the same for him through tumultuous love affairs, social humiliations, thwarted ambitions, and the general political unrest in Paris. On some level, Frédéric must realize this, since he never takes an aggressive step to conquer her physically. Madame Arnoux, however, makes her gravest error when she finally offers herself to him. Misunderstanding her role in his life, she tries to cross the line from mother figure and constant companion to lover, which marks the end of their relationship.