[Lane is arranging afternoon tea on the table, and after the music has ceased, Algernon enters.]
Algernon. Did you hear what I was playing, Lane?
Lane. I didn’t think it polite to listen, sir.
Algernon. I’m sorry for that, for your sake. I don’t play accurately—any one can play accurately—but I play with wonderful expression. As far as the piano is concerned, sentiment is my forte. I keep science for Life. (Act I, scene i)
The opening lines, Act I, scene i (above), are richly demonstrative of a comedy of manners. These lines represent a true-to-life picture of England's upper class manners and ideas: one is paramountly polite; science and sentiment may be kept separate from each other.
A quick definition of drama that is comedy of manners is that it is theater that displays an honest representation of contemporaneous upper class life while revealing the artificiality that underpins it through satire. Satire is the attempt to use pointed ridicule and humor to uncover an error of society, a group, or an individual. The sole aim of satire is to break the comfortable disregard of social agreement on what is right behavior and provoke a change for the better.
The quote above reveals upper class artificiality and pretense through brilliantly witty humor in order to provoke a renewal of sincerity and integrity.
Cecily. ... You know German, and geology, and things of that kind influence a man very much. [Cecily begins to write in her diary.]
Miss Prism. [Shaking her head.] I do not think that even I could produce any effect .... Indeed I am not sure that I would desire to reclaim him. I am not in favour of this modern mania for turning bad people into good people at a moment’s notice. As a man sows so let him reap. You must put away your diary, Cecily. I really don’t see why you should keep a diary at all.
Cecily. I keep a diary in order to enter the wonderful secrets of my life. If I didn’t write them down, I should probably forget all about them. (Act II, Scene i)
The above quote from Act II, scene i, reveals the social artifice and false superiority that may be attached to upper class education and the popular trend for "reclaiming" young men who have adopted lives of vice instead of virtue. In this scene, Cecily's governess denounces the practice of "turning bad people into good people at a moment’s notice," while Cecily records moments and ideas so trivial that, were they not recorded in her ever so fashionable diary, they would vanish from thought. Satire in this element of the comedy of manners is aimed at exposing the false values in what was then upper class education with the aim of reclaiming it to its former virtue of seriousness and thoughtfulness.