“Madam,” responds Boyer to Eliza. “The regard which I felt for you was tender and animated, but it was not of the passionate kind which ends in death or despair.” Boyer tells Eliza that her previous conduct convinced him that his regard was “misplaced,” and that she does not possess the “charms which [he] had fondly ascribed to [her].” Boyer goes on to say that through “artifice and dissimulation,” Eliza “strove to render [him] the dupe.” He has recently been married to a “virtuous,” “amiable,” and “accomplished” women, and while he will always “cherish sentiments of kindness towards [Eliza],” her letter “came too late.”
Boyer’s response to Eliza is condescending and clearly meant to make her feel even worse. He basically tells her that he never really loved her that much, so it makes no sense for her to pursue him or continue to pine for him. He tells her he has married a “virtuous” woman, which is to say that Eliza is not a virtuous woman, but what’s more, he insinuates that any feelings he may have felt for Eliza in the past were never really there in the first place.