What philosophical issues does Oedipus face in Oedipus the King?
Oedipus is faced with philosophical issues concerning fate.
Fate is sometimes a confusing subject in regards to its role in a story. In Western storytelling it's often seen as a binary good-or-bad force with mysterious origins and powers. The "good" facet is often used in relation with words like "destiny", and the "bad" aspect in relation to words like "doom". Fate is often seen as something to be embraced if it's good, or avoided if it's bad. Many modern stories make use of the trope wherein a character "escapes their fate" through force of will or by undertaking specific tasks (a good example would be Luke Skywalker's rejection of his "destiny" to turn to the Dark Side).
This makes fate out to be something one can disagree with, like fortune-telling, or something that possesses a personality and decision-making of its own, but is only slightly more powerful than the average person since it can be "defeated" with enough skill, luck and guidance. So, fate is often employed as a "man vs. nature" or "man vs. himself" conflict.
While elements of these conflicts are apparent in Oedipus, the moral of the story is more definitive; it is a "man vs. God" conflict, one which the man can't win. Fate, in this play, and in much of Greek tradition, is not something that can be altered or rejected. It is a course set by the universe itself, something that not even the gods can alter (in fact the gods were known to be less powerful than the Fates and subject to their decisions).
Oedipus faces several issues;
- Should he consider the prophecy to be fate? Just because someone says "X will/won't happen" doesn't mean it's an actual prophecy or fate, but this message came from the oracle at Delphi; it would be hard to find a higher authority on Earth.
- Should he attempt to reject his fate? No matter the reason, this would imply that he thinks he can defy the universe, a pride which cannot go unpunished in itself.
- If he rejects it, in what manner does he do so? A wise character might be lauded if their defiance is undertaken for noble causes, such as protection of the innocent, whereas a character rejecting fate for the purposes of their own satisfaction and fortune will be cast as foolish and deserving of punishment.
- If he accepts it, does his humanity diminish? It might be argued that any truly "human" character will reject fate because they don't really know what's best for them (note that the Greek concept of free will, if it existed, didn't match our own, and that what we call free will was more likely to be interpreted as a cause driven by some force other than divinity).
Oedipus learned of his fate upon visiting the oracle, and his response was to reject it by running away. He did so in order to protect those that he loved. It seems that it never occurred to Oedipus that his "parents" might not in fact be his birth parents, nor did the oracle choose to specify this. There's no way of knowing if Oedipus's decision to run away is what directly led to the murder of Laius, or if Laius would have found his way to death at Oedipus's hands even if Oedipus had stayed home. This ambiguity is what lends fate its power in this story.
The redeeming element might be that Oedipus is not the prime actor in this prophecy. Laius and Jocasta were initially given this prophecy, and their abandonment of Oedipus as an infant was, in fact, the first rejection of the prophecy. Oedipus rejected the prophecy out of compassion for others, whereas Laius and Jocasta rejected it out of fear for their own lives. Since Oedipus ultimately accepts his fate, I think he can be considered a tragic hero rather than someone entirely "deserving" of his fate.