In at least 200 words, explain how the following line, which oedipus says in the first episode, supports the play's major themes: oedipus: this polluting stain i will remove, not for some distant friend, but for myself.

One major theme in Oedipus is that of the effects of pride. In fact, this play supports the maxim: "pride goes before a fall."

With these words, Oedipus shows his great pride. He wants to remove "this polluting stain" for himself, not for someone else and not for his city or its people. He is motivated purely by pride. His pride, of course, also led to the death of King Laius, creating "this polluting stain" in the first place. 

His pride will ultimately lead to his downfall. In this case, his pride went before his fall.