What walks on four legs in the morning, two at noon and three in the evening? This is the riddle of the Sphinx from Oedipus Rex, the world’s most (in)famous play. If he fails to penetrate the mystery, his mortality will be proven.
Humans, he answers, who crawl on four legs as babies, who stand on two feet as adults, and who, with a cane, age. Aristotle articulates the same alignment of mortality with the solar cycle in Poetics, the first canonical text on storytelling. “Old age is to life as evening is to day; accordingly, the poet will speak of evening as ‘the old age of day’ and of old age as the ‘evening of life’ or (as Empedocles puts it) ‘the sunset of life” (Poetics, 25).
Before writing his treatise on storytelling, Aristotle would have seen Oedipus Rex, which transmutes the alignment of life and day into Oedipus’ story. As it goes, he is abandoned as an infant and grows into an adult, before, as prophesied by Tiresias, he “grop[es] the ground… with a stick” (Sophocles, 560).
The riddle—understood, at least, by such narrative greats as Sophocles and Aristotle—is quite astounding. Not only does it demonstrate an ancient religious alignment of life and day; but insofar as the riddle occurs within one of the greatest plays of all time, and insofar as the answer defines the structure of its protagonist’s arc, it also demonstrates the transmutation of solar-life cycles into character arcs and narrative structure. At the same time, its tripartite sequence can be seen as a forerunner to Aristotle’s emphasis on beginning, middle and end.
Earlier examples of this alignment can be found in the conflation of Osiris' life cycle with that of day and night. As the eye of Horus, his sun, is punctured at sunset, so, too, are the eyes of Orion, with whom Osiris shares a constellation. This is why the image of an aged Oedipus is incomplete before his eyeballs are popped. We age into blindness as sunset brings dark. But in the cases of Horus and Orion, who journey through night, their eyes come back with the sun.
To death or renewal, each example demonstrates how day and mortality can be fused into a dramatic arc and character journey.