Marriage is discussed from four different perspectives in Oscar Wilde's The Importance of Being Earnest, act I: it is viewed from the points of views of Lane, Algernon, Jack, Gwendolen, and Lady Bracknell, in that order. However, the main argument during this act contends that marriage is:
Demoralizing: Algernon's valet, Lane, discusses marriage with Algernon when the latter wonders how come champagne seems to disappear in a bachelor's home. Lane responds that wine is often a much better quality when one is single, to which Algernon responds with the question of whether marriage is really "that demoralizing"?
Pleasant, but only for some people: Lane's answer to Algernon is that he, himself, understands that marriage may be a pleasant state but that he has had very little experience about that.
"Not a very interesting subject": Algernon refuses to continue the conversation about married life with Lane, and the latter seems to gladly end the conversation as well claiming the lack of excitement that comes from the topic.
Predictable: When Jack announces his idea of marrying Gwendolen, Algernon's cousin, he argues that Jack will kill the very idea of romance with the words:
The very essence of romance is uncertainty. If ever I get married, I'll certainly try to forget the fact.
Sanctimonious: Algernon argues that
The amount of women in London who flirt with their own husbands is perfectly scandalous. It looks so bad. It is simply washing one's clean linen in public.
Clearly, he prefers a tint of maliciousness than wholesomeness when it comes to relationships.
Tedious/Boring: Algernon introduces Jack with the concept of Bumburyism, which is to create an imaginary "someone" (in Algernon's case it is a disabled friend named Bunbury) who happens to calls us for help in the precise moment when we are stuck doing things that we do not want to do. Algernon claims that marriage without Bunbury is no marriage at all.
A man who marries without knowing Bunbury has a very tedious time of it.
Similarly, Lady Bracknell explains the tediousness of marriage by explaining to Algernon how her friend became younger and better looking after the death of her friend's husband.
I was obliged to call on dear Lady Harbury. I hadn't been there since her poor husband's death. I never saw a woman so altered; she looks quite twenty years younger.
Transactional: Both Gwendolen and her mother talk about the process of courting and marrying for specific purposes. Gwendolen only will marry a man if his name is Ernest while her mother looks at specific traits to allow the marriage. At any rate, it is the guardian or parent who decides and not the child. Just like Jack forbids Algernon to come near Cecily, Lady Bracknell forbids Jack to come near Gwendolen.
When you do become engaged to some one, I, or your father, should his health permit him, will inform you of the fact. An engagement should come on a young girl as a surprise, pleasant or unpleasant, as the case may be.
Those are the basic premise of marriage in act one.