“When I say ‘I will be true to you’ I must mean it in spite of the formalities, instead of the formalities. If I commit adultery in my heart then I have lost you a little. The bright vision of your face will blur. I may not notice this once or twice, I may pride myself on having enjoyed those fleshy excursions in the most cerebral way. Yet I will have blunted that sharp flint that sparks between us, our desire for one another above all else” (Winterson 79).
I believe that through this passage the narrator tells us that loving another person, giving yourself to them and only them, is a conscious, continuous action. Love is constant in its demand of your entirety; at even the smallest provocation of infidelity, your love will have lost a part of you to another. When Winterson says “in spite of the formalities, instead of the formalities” she is referring to marriage and courtship (79). As both marriage and courtship unite the individuals in the relationship by binding them by societal ties of belonging, Winterson declares that these unions are separate from the commitment of love. A person might be bound to another by marriage or courtship but their love might not truly belong to their partner if they “commit adultery in [the] heart” (79). If your love, desire, is given to another even if only for a second, then you will have “blunted that sharp flint that sparks between us” (79).
At this point in the novel, we know that the narrator has had numerous prior relationships that have been adulterous. By fantasizing and dreaming of Louise, the narrator has actively estranged herself from Jacqueline. This passage is about that narrator letting go of their relationship with Jacqueline, all the possibilities of a life between them, and of Jacqueline herself. The narrator identifies that her adulterous thoughts and desires for Louise “blunted” her interest in Jacqueline (79). While recognizing this, the narrator simultaneously pledges a vow to Louise to constantly affirm their love for her: to banish all thoughts of past lovers and forever cherish her above all else.