What is the meaning of the title The Importance of Being Earnest?
The title of Oscar Wilde's most successful playThe Importance of Being Earnestfeatures a salient pun in the form of the word "earnest", which means "honest", and "truthful" and the name "Ernest" which is the name of the alter ego that main character Jack Worthing uses to slide away from responsibilities and do as he pleases.
The reality is, however, that nobody in the play seems to be very "earnest" as it is. Algernon proudly and blatantly lies just about everything under the sun while Jack criticizes Algernon. This, he does while Jack ALSO lies about this so-called bad brother named Ernest whom he has to rescue all the time by going to the city and staying there paying for all his follies. This same "Ernest" is the man that Algernon met for the first time. Remember that Algernon only comes to find out about Jack's real name when he accidentally finds "Ernest's" cigarette case with the inscription made to "Uncle Jack". Likewise, Jack also lied to Gwendolen by presenting himself as "Ernest".
What is important, however, is that the title of the play reflects that there is something valuable and even honorable about being "earnest", or honest. However, all the while everybody in the play has lied to each other in one way or another. The end is even more ironic; all the lies that Jack said...were actually true! When he finds out about his dead parents, and realizes that his name is dully Ernest, and that he does have a brother (Algernon), and that all this time he had been speaking out things that were actually true, Jack sanctimoniously says (which is even more ironic) "now I know the vital importance of being earnest"...in other words, he is basically saying "WOW, I was right all along? Then, yay for me!"
This is a direct hit from Wilde to all those prudish and so-called virtuous Victorians whom he detested more than anything. He mocked them directly in the play by exposing them for the claccist hypocrites that they really were.