Women
The question of a woman's role in society is brought to the foreground in some progressive (and some not so) in The Way of the World. Like baking cookies, we are introduced to the mixing of the two gendered factions of Restoration society, men and women, separately before they are mixed all together. The women, when we first meet them in early Act II, are discussing the need to find happiness in one another since men only provide a fickle, distrustful love that cannot be relied upon. However, the audience comes to realize that these women are not totally trusting of one another either; they love the same man and turn against each other in later schemes to ensure the romantic and monetary outcome they want. The freedoms a woman can have in and out of marriage are also shown and discussed in the play, from the famous "proviso scene" to Lady Wishfort's ability to overlook Waitwell's disguise for the chance to marry a man at an older age.
Marriage, Adultery, and Inheritance
Marriage and adultery are of course main themes in The Way of the World, and it seems that characters have much more of a problem with the potential for a tainted reputation than with any moral or emotional imperative not to cheat on their spouse. This starts in the first place with the problem that, though the primary marriage being arranged in the play seems to be based on love, many of the marriages set in place before the play, like Mrs. Fainall's marriage to Fainall, were done more tactically as ways to ensure money and reputation. A major conflict in the play too is who will have claim to Ms. Millamant's inheritance, with Fainall attempting to leverage his wife's apparent adultery to get claim to her, and Ms. Millamant's, inheritance.
Friendship
Same-gender and opposite gender friendships are called into question in this play, as it is said and demonstrated that none of these relationships is particularly strong or trusting. The women-women and men-men pairings, though originally posing as friends, join schemes against one another based mostly on money and reputation. As for women-men pairings, we do not see many in the play that are not based on either mutual love or the love of one and disdain of the other. Certainly, friendship is as falsely fashionable and tactical as anything else in the play.
Religion
The characters in the play throw around invocation of God, as in "Odso", all the time, but this is used basically as a flippant linguistic note, and often said colloquially in the same way people in contemporary society throw out "God bless you" without a thought. Mention is also made of drinking and religion, with reference to Islam. However, it is important to note that accusations of adultery do not seem to be based in a religious morality, and women seem to keep in mind the ability to divorce (Mrs. Fainall seems largely undisturbed by the fact that she and Fainall cannot stay married after the play's end).
Money
Money and love are tied closely in The Way of the World, and perhaps as much as reputation, Lady Wishfort's fate after the play rests on her being able to dole out inheritances appropriately. However, as members of the upper class, much regarding money is dealt with quite flippantly, like having dance performers over at the house or, early in the play, ordering chocolate and drinks. It is important to note that Ms. Millamant's half-inheritance of 6,000 pounds would amount today to many, many thousands of dollars, making the point of multiple characters lusting after it more clear.
Social Class
The presence of two main classes in the play - upper class and servants - calls attention to social class as a theme in the play, though one that is not written with the satirical eye Congreve gives to upper class behavior alone. As Congreve writes it, Foible and Waitwell, servants to Lady Wishfort and Mirabell, seem delighted to be married against their will and participate in a romantic scheme at the beck and call of Mirabell. This is perhaps not true to life, though it gives them both the ability to exert secretive power over members of the upper class. Within the upper class, it is also demonstrated through jokes about one another that being well-educated and well-mannered is of utmost importance, and there can be social division atop economic based on these elements of etiquette and status.
Social Etiquette and Reputation
"Why do we daily commit disagreeable and dangerous actions? To save that idol, reputation." (Act II, Scene II)
A Comedy of Manners is named as such to call attention to one of its most central themes - manners, or social etiquette, and the comedy that can ensue because of the importance, especially to the upper class during the Restoration, of preserving one's position in society. In the climax of the play, the actions and reactions largely stop being concerned with love or even money, and what Lady Wishfort seems to fear most is a loss of good reputation for herself and her daughter. Much of the demonstrated love seen in the show - for example, Witwoud and Petulant's love for Ms. Millamant - is done purely in hopes of raising one's reputation. Fun is made of social etiquette especially in the acting of Petulant, Sir Wilfull, and Sir Rowland, three characters that to varying degrees are unable to live up to upper class standards, but must try to put on a show for others.