Oedipus Rex: Discussion Question

Tiresias the Prophet says on page 13, "I am Free! for I have in me the strength of the truth." Meanwhile, Oedipus is uncovering the truth of his past, and it proves to be his undoing. Truth versus ignorance is a strong theme throughout Oedipus Rex. Trace it through the text and analyze its significance. What is Sophocles saying about the place, role, or implications of Truth in society?