In Sophocles’ play Oedipus Rex, Jocasta makes a number of assertions about prophecies. At one point, for instance, she says that “no human being has skill in prophecy” (852), and she offers as evidence the fact that her former husband Laius was told that he
was fated to be killed
by a child conceived by him and me. (857-58)
She regards this prophecy as false and uses its supposed falsity as a reason for denying the truth of prophecies more generally.
Later, after Oedipus slowly realizes the truth of this very prophecy, the chorus shows its faith in prophecies in general and regrets that they are not taken more seriously:
For ancient oracles which dealt with Laius
are withering—men now set them aside.
Nowhere is Apollo honoured publicly,
and our religious faith is dying away. (1074-77)
Jocasta then re-enters the stage and criticizes Oedipus for listening to “whoever speaks to him of dreadful things” (1087). At this point, then, she still seems skeptical pf prophets and oracles. Later, of course, she agonizingly realizes the truth of the prophecy about Oedipus, and she kills herself after realizing that she has unintentionally married her own son (1477).
The chorus, of course, took prophecies and oracles seriously from early in the play, as when the Chorus Leader, advising Oedipus on how to discover the murderer of Laius, says
As for what you’re seeking, it’s for Apollo,
who launched this search, to state who did it. (326-27)
In fact, it is the Chorus Leader who first suggests that Oedipus should consult the prophet Tiresias (333-34). Thus, by the end of the play, the faith of the chorus in prophecies and oracles in general, and in Tiresias in particular, is shown to be sensible, while Jocasta’s doubts are revealed to be merely wishful thinking, however plausible they may have seemed at first.
(Ian Johnston translation; see link below)