In Sophocles’ play ‘Oedipus Rex,’ the Sphinx poses a riddle to every traveler on the road from Thebes to Delphi and in order to pass, the traveler must answer correctly or be strangled by the Sphinx. Although Sophocles never wrote the actual riddle in the play it is generally held that the riddle follows thusly: What has four legs in the morning, two legs in the afternoon, and three legs at night? When Oedipus answered correctly that ‘Man crawls on all fours as a baby, walks on two feet as an adult, then walks with a cane as an elderly person’ the Sphinx was so astonished that she threw herself into the sea, and Oedipus went on to Delphi to fulfill his destiny as prophesied by the oracle.
