I re-read the ending of The Importance of Being Earnest and it is strikingly Oedipus Rex in reverse. Oedipus doesn't know or think he knows who he is and finds out. It is a tragic event that leads to much suffering. Jack finds out who he is and it brings everybody in his live together and connects them where in Oedipus is tears them apart. I guess that is the quintessential difference between comedy and tragedy. There is a line in The importance of Being Earnest that I really enjoyed and here it is...

"I hope it did not end happily? I don't like novels that end happily. they depress me so much." -Cecily

"The good end happily. the bad end unhappily. That is what Fiction means." -Miss. Prism

I believe this is a good reference to my statement above and the difference between the two stories. Comedies end happily and Tragedies end unhappily. I liked Cecily's line earlier because it means that there is much to learn about tragedies. That even though they are unhappy endings, we can constructively learn from them as well as comedies.