I think the main theme of the play is dishonesty. Almost everything the play is at least slightly untruthful and all of the only character that I think didn't lie was Merriman. I think that everything that could possibly have been made fun of in that time period was. One example was when Algernon said to Jack "What a fearful liar you are Jack, I haven not been called back to town." because Algernon came to Jack's house and lied about who he was. Everyone seemed to think that marriage was just a "buisness arangment" and it was common sense that one person in the relationship would always go "Bunburrying". The whole thing is a lie, because the people didn't always go Bunburrying, and Bunburrying is lieing. Also, there was a huge issue going on about the people living in the city bieng more intelligent and "fashionable" than the people who lived in the country, which wasn't neccisarily true. The Earest/Ernest thing is pretty easy to explain. It's really ironic because earnest means honesty and Jack lied about his name being Ernest (and it turns out his name is actually Ernest in the end, but still). The last one, the pursuit of pleasuer is also dishonest, because everyone lies to be happy, yet it's frowned upon to live just for pleasure.
I think that Wilde seems to be saying a lot of things about dishonesty through the play, and most of them have to do with society. I'm not sure whether he's saying it's okay to lie or not though. I seemed like most of the characters lied for pleasure or to get revenge at other people (which also gave them pleasure). All of the dishonesty that the characters had seemed pretty innocent. I think he might have been trying to say that people lie to make their lives better/more interesting. Jack and Algernon just made people up to go and have fun, and Cecily made up Algernon because she was bored and kind of insane. Lane lied for Algernon, but that was because he was working for him. Lady Bracknell lied to cover up the truth from her husband but in the end that was for pleasure too.
