Why does Tiresias initially refrain from divulging the truth to Oedipus and assembled others?
Tiresias did not want to reveal the truth to Oedipus because he felt sorry for him and did not want Oedipus to suffer. He knew that the king was a good man, and having known the terrible truth would make his life change completely. The prophet also did not want to reveal the truth to others because he could guess the consequences of opening such facts. People might get outrageous and thus would want to do harm to Oedipus, his wife (who was his mother at the same time) or his children. There might be one more reason why Tiresias wanted to keep the secret. As a wise man, he was thinking about the consequences not just for Oedipus but also for the country. After the truth is revealed, Oedipus would have to leave his throne anyway, and changing the leader is always a painful experience for any country.
Why do you think Sophocles decided to make Tiresias blind?
First, I do not think that it was Sophocles who made Tiresias blind. This prophet appears in other myths being blind in all of them as well. However, in this very tale, Tiresias’ physical blindness is just the way to show what real blindness is – the blindness of a heart or inner blindness. Though Oedipus was not blind in the physical meaning of the word, he could not see the terrible sins he did. After Tiresias had told Oedipus the truth, Oedipus did not believe him and accused the prophet in saying lies and mocking at his physical blindness. The revealed truth seemed unbelievable to the king, and he did not want to accept it finding for him the reason not to trust the prophet — his blindness. To see means to be able to differentiate the truth and the lies, the god and the evil, and then who is really blind — Oedipus or Tiresias? Obviously, it is Oedipus. The story ends up by Oedipus depriving himself of his eyesight, and thus Sophocles shows that being physically blind means nothing to being blind inside.