Abstract: Drawing upon 1800 letters, 500 of which have not been published before, the figure of Angélique Arnauld (1591-1661), the reformer abbess of Port-Royal, is revealed: she is strong-willed and strict. However, Angélique Arnauld expresses her pained helplessness in the face of royal sanctions against those who were from then on called the Jansenists.