Jean-Paul Sartre, as an existentialist, puts at the center of his works the question of freedom and responsibility. Existentialism posits the idea that “existence precedes essence,” thus leading to the conclusion that one is only what one makes him or herself to be through his or her actions; no purpose or meaning is pre-given to individuals. Sartre seems to be completely rejecting any ideas of determinism or fate as factors influencing one’s life. The Greeks, on the other hand, speak constantly of the impact of fate and the actions of the gods on the lives of individuals. Perhaps the most well-known example is that of Oedipus; a prophecy is made about him before he is even born, that he will live to kill his father and marry his mother. Despite his best efforts to avoid this prophecy, Oedipus inevitably fulfills it. In fact, specifically in trying to avoid fulfilling the prophecy, Oedipus is helping to bring it about, as when he leaves Corinth after hearing the prophecy for the first time (under the false impression that the king and queen of Corinth are his true parents and it is to them that the prophecy refers). This, of course, is what brings him once again face-to-face with his real parents (although none realize this). These two views of freedom and determinism seem to be entirely at odds with one another; how can one freely choose when the course of one’s life has already been set out? This paper seeks to consider the questions of fate and free will in Greek mythology and existentialism, specifically looking at Sartre’s play, The Flies.