Greek values centered in reason, order, and moderation. To understand the Greek culture or understand the literature of the time, it is important to have a grasp of these concepts and their influence on the Greeks.
Around 500 BC the Greeks began to move away from the mythos, relying on the gods and myths to explain the unknown, to logos or logic, where an explanation was formed through sound thought or reason. Reason is exemplified in Greek culture through various avenues. Famous philosopher and student of Plato, Aristotle developed theories that were very rational. Aristotle encouraged notions of moving toward a more rational deduction of the unknown, called Empiricism, the idea that what you see is what you get. Art created before 500BC was also based much more heavily on the gods and the idea of the mythos. Statues depicted Greek gods and myths, not the everyday man, which started around 500BC (1260 BC of the Four Seated Figures of Ramses II). An example of moving away from the mythos into the logos, or reason, would be the statue of Doryphores, the spearbearer, which moves away from depiction of gods and exhibits a new face of reason and rationality. The public during this time was erecting statues of common citizens, like the Spearbearer. This was something completely new, even just looking at his stance, he no longer stands rigidly upright, he appears as though he has options, he can either take a step forward or a step back. He represents new rational decision making independent of the gods in part or in whole. Another medium in which reason is evident is through the play, Oedipus in which Oedipus really is a very rational and reasonable person, as he should be being king of Thebes. He does ask the gods for help but he also chooses to take on the responsibility to help rid Thebes of the Plague. Oedipus fears he may suffer the same fate as Laios if he does not banish his murderer, a highly rational decision especially considering that it was not specifically what the gods asked.