As we discuss in "In A Nutshell," The Flies builds on the Greek myth of Orestes and Electra. Because it does so theatrically, it falls into the "Drama" genre as well. The parable aspect of the play comes in when you consider the context in which Sartre was writing, and the commentary he's making on the Nazi occupation of Paris. In this parable, rulers like Zeus and Aegisthus represent organizations like the Nazis (or organized religion, or any other external system of rules forcibly imposed). The citizens of Argos are then the citizens of Paris, and Orestes an idealized, would-be savior.
The Flies is also a literary exploration of Sartre's philosophical ideas. The play was published in the same year as Being and Nothingness, Sartre's philosophical treatise that firmly established the foundations of what he named "existentialism." What is existentialism? That's a big question, and not one that we can answer in a few sentences for you. Part of the problem with talking about this philosophy at all is that the different thinkers who are labeled "existentialists" had very different ideas (and almost all of them declared to their death that they were absolutely not existentialists). So when we talk about "existentialism" in this Shmoop Guide, we're talking about Sartre's version of existentialism.
So what is Sartre's version? The simplistic definition is that existence precedes essence. Existence is the fact of being around at all. You exist, a hat exists (though not in the same way), a cat exists, etc. Essence is what you are – it's your function, your nature, your definition. Sartre believed that we have no pre-programmed essence, no definition of what we should be, no preconceived expectations for what to do or how to act or what to be. We exist first, and then we define our own essence through our choices and actions. We can choose to do anything – we have radical personal freedom – but we also have radical personal responsibility for the choices that we make.
In particular, The Flies focuses on this idea of personal freedom. Sartre maintains that no one has power over you until you give him or her that power over you. Think about that moment when you were a kid and you suddenly realized you could say "no" to your parents. Sartrean existentialists experience that sort of epiphany for all systems of authority – the police, the lawmakers, or your boss. When we recognize this freedom – when we truly realize its consequences – we experience what Sartre calls "anguish." We're terrified by it, and we're tempted to retreat into "bad faith" – a form of self-deception in which we pretend we're not free so we don't have to deal with the scary aftermath.
One way of engaging in bad faith is to give our freedom up to other people – like our boss, the police, or lawmakers. We stop existing as human beings should exist (an active, conscious mode of being called being-for-itself) and we start trying to exist in a weak, inactive form of being called being-for-others, a type of existence in which we refuse personal responsibility and allow others to define who we are.
The Flies examines these ideas of personal freedom as well as the consequence of being-for-others. It embraces a life of "authenticity" and condemns bad faith.