Affectation
Nearly all of the characters in the play are well versed in affectation, meaning that they disguise their true feelings, emotions, mannerisms, and beliefs behind a wall of artifice. This is done to conform to society's expectations that their outer appearances does not match their inner life; thus, roiling emotions, immodest inclinations, bouts of anger or despair, or anything else that may be considered improper to air to one's companions are kept submerged. It is a veritable game that the characters must play. Those who are skilled at it, such as Dorimant, are admired, while those who do not quite understand what is expected of them, like Sir Fopling, whose affectation is bombastic, are ridiculed. Etherege generally supports this reality of his day, but through Harriet also demonstrates how being a little more authentic is both possible and laudable.
Marriage
The play generally has a positive view of marriage, but it takes awhile for it to manifest itself. Young Bellair and Emilia want to marry, and we largely understand and support their desire to do so, but the protagonist, Dorimant, spends most of the play ridiculing the institution and reveling in his affairs and exploits. He does not want to be trapped by oath or claim or contract, and with women such as Mrs. Loveit, that makes sense. However, the play becomes much more traditional by the end when Dorimant meets his match in Harriet and decides that he is indeed the marrying kind. The play ends with one marriage (Bellair and Emilia) and an engagement, which shows Etherege conforming to a positive view of marriage, but also demonstrating that marriage is best when it is entered into freely and with wisdom and discernment.
Manners and Decorum
Every character in this play seems to be obsessed with their actions and the actions of others. They critique, complain, and monitor each other; sometimes they try to do the same for themselves (but not as often, of course). Sir Fopling's manners and decorum come under the greatest of scrutiny; he is certainly mannered and decorous, but has taken that to an excessive level. He is called "insipid" and "pert" by the circle, although they do admit that his manners are polished enough that he may fool others, who might therefore consider him a great wit. Mrs. Loveit, by contrast, has few manners. She is also ridiculed, mostly because she cannot control herself or exercise restraint or decorum. Her rages and tantrums reveal her as a woman lacking modesty and class, and that, according to Etherege and contemporary audiences, is a grosser offense than being a fop or a fool.
Tradition vs. Modernity
A few of the characters represent tradition, while others represent modernity. In their views on marriage and modesty, as well as their way of conducting themselves, Old Bellair and Lady Woodvill represent a more traditional, old-fashioned worldview. Mrs. Loveit also represents this, as she has an outmoded view of love and courtship. Young Bellair and Emilia represent a middle perspective, as they value traditional marriage but are open-minded to new modes of behavior. Medley, Dorimant, and Harriet are more modern because they are completely open and/or accepting of the new norms of sexual behavior and marriage as a match of equals.
Folly and Foppishness
The play's great strength comes from its wittiness in exposing and critiquing folly and foppishness. While all of the characters have some degree of undesirable characteristics (Dorimant is a womanizer; Belinda is self-interested; Harriet is cruel), Sir Fopling Flutter is the main target of censure. He certainly knows a lot about dress, but that is it. He has no substance, no inner being. He tells Dorimant he needs more mirrors, and comments tellingly "In a glass a man may entertain himself" (118). His affectation is all there is to him.
Disguise
Nearly all of the characters use disguises of a sort. Belinda is introduced as a masked woman, and she lies to Mrs. Loveit and says Harriet was as well. Feelings are hidden and masked, such as Harriet's true feelings for Dorimant, Belinda's role in the plot to embarrass Mrs. Loveit, Dorimant's plans for his lady loves. Even the "pure" love of Emilia and Young Bellair is hidden, and he and Harriet play their role as a besotted betrothed couple. Fopling wears a mask to one of the gatherings as well, but as he has nothing to hide because he has no inner life, he is encouraged to take off the mask. Everyone else, though, wears their masks almost all the time, and it takes a special occasion, such as Harriet finally getting Dorimant to be authentic with her, for them to drop them.
Social Class
While this theme is not as obvious as others in the play, it is still there lurking beneath the surface. Comedy in the Restoration era used the exploits of the rich as the basis for its plot, reveling in the glittery, amusing milieu in which these men and women operated and schemed. Their follies and mistakes were fodder for critique and commentary, and, of course, humor. However, there are also lower-class characters in this play too: the orange-woman, the shoemaker, and the waiting women Busy and Pert. Etherege gives the waiting women some clever lines and amusing moments, and allows the orange-woman to perform the crucial act of introducing Harriet to the story, but overall they are not significant to the drama. Etherege's is the world of the rich rake, the masked woman, the titled fop, the prudish Lady, and the beautiful heiress.