Can You Solve the Sphinx’s Other Riddle?

By Dr Oliver Tearle (Loughborough University)

One of the most celebrated tragedies of ancient Greece was Oedipus Rex, Sophocles’ play about the Theban king who unwittingly killed his father and married his mother. In order to become King of Thebes, Oedipus had had to solve a famous riddle – or should that be riddles?

Oedipus was born to King Laius and Queen Jocasta of Thebes, but when Laius hears a prophecy that he will die at the hands of his son, he orders the child to be killed. The infant is left on a mountain to die, but a shepherd finds him and takes him in, raising him as his own son and naming him Oedipus (literally ‘swollen feet’, from the pins that had bound the infant’s feet together when he was found).

When he grows up in Corinth, Oedipus learns of the prophecy that he will kill his father and marry his mother, and thinking that the shepherd and his wife are his real parents, he flees the city in order to ensure such a fate never befalls them – only to run into his biological father, Laius, on his way to Thebes. The two men fight and Laius is killed.

Oedipus then arrives in Thebes to find that the king has recently been killed, but poor Swollen-Foot doesn’t think to put two and two together. Instead, he becomes king, marrying the widowed queen (whose name is – you’ve guessed it, Jocasta) and having children with her.

Later, Oedipus learns of what he has done, and blinds himself; Jocasta, upon learning that she’d borne her own grandchildren with her son, hangs herself.

We’ve written about the story of Oedipus previously, in our brief history of tragedy. The story of Oedipus gave Sigmund Freud, father of psychoanalysis, the idea for his theory of the ‘Oedipus complex’, where every male child harbours an unconscious desire to do precisely what Oedipus inadvertently did.

The child has to repress this desire, but is often only partly successful (Shakespeare’s Hamlet, for instance, doesn’t fully manage it, according to Freud’s reading of the play – a fact that numerous theatre and film directors have seized upon, especially when portraying Hamlet’s frustration at his mother’s remarriage to his uncle).

Oedipus got the job of King by solving the famous riddle of the Sphinx and removing the plague that had been ravaging the city. The riddle is fiendish, but has a simple answer. ‘What goes on four legs in the morning, two legs in the afternoon, and three legs in the evening?’

The answer? Man, who crawls as a baby, walks on two legs as an adult, and uses a walking stick in his twilight years. (Apparently cat-women hybrids posing conundrums was the way you advertised the job of new king in ancient Thebes, as Monty Python might have put it.)

But was this the only riddle Oedipus had to solve? Yes and no. In Sophocles’ play, probably the most famous retelling of the story, it certainly is. But some versions of the Oedipus story have a second riddle for him to solve. A Gascon version of the myth, for instance, has the Sphinx posing this follow-up question: ‘There are two sisters: one gives birth to the other and she, in turn, gives birth to the first. What are they?’

Before reading ahead to the answer – yes, *spoiler alert* – can you cut through the Sphinx’s riddling talk and do as Oedipus did? (By solving the riddle, we mean, not the – er, other stuff.)

If such a family set-up sounds as unconventional as Oedipus’ own, then the answer at least puts us at our ease. The two sisters are ‘Day’ and ‘Night’.

Perhaps the Sphinx should perhaps have stopped at the first riddle. It was certainly her stronger material. And she did the right thing in choosing to open with it.


  1. Hmmm night and day?

  2. ok i got it instantly !
    what do i win? :P

  3. Reblogged this on axelpua.

  4. In high school I took a Greek mythology class. It was fun.

  5. day and night perfect..

  6. I just got a flashback to my university lectures on Sophocles’ plays! Ahhh find memories 😀

  7. Very interesting literature indeed ;-) Thanks for sharing.

    Be Blessed!


  8. Day and Night? Pah! I would have posited the Old Moon and the New Moon: one follows the other as the night follow the, uh, day. OK, scrub that. Or the two sisters could be the tides…

  9. Cause and effect?

  10. la mythologie grec, c’est ma grande passion.

  11. That was my guess, too. However, had I been a editor in ancient Greece I’d have thrown away the manuscript to this tale of woe. Poor Will — I think he’d be astounded to know what Freud has read into Hamlet’s grief.

  12. I was going to ask if it was the sun and the moon haha