Euthyphro

The Platonic dialogue Euthyphro takes place as Socrates is on his way to court. He is under indictment for the corruption of the youth of Athens, and meets Euthyphro, a priest who is prosecuting his own father for murder. The dialogue quickly becomes a discussion on the nature of piety. But although Euthyphro appears to be considered an expert on morality and piety, he proves himself to be a typical beginner, out of league with the professional philosopher Socrates.
Euthyphro and Conviction
Euthyphro defends his actions with conviction: "I say the pious is to do what I am doing now, to prosecute the wrongdoernot to prosecute is impious". Socrates hopes to get to the heart of the matter. Euthyphro has defined his actions as pious, but failed to define what pious is. Socrates has asked for the form of pious, "so that I may look upon it, and using it as a model, say that any action of yours or another's that is that kind of pious, and if it is not that it is not". Socrates is introducing the Platonic idea of the form, Plato's belief that everything in the universe had a cosmic model of which the things in the real world were but reflections.
Euthyphro and Socrates
Euthyphro's answer, of course, is: "what is dear to the gods is pious, what is not is impious". Socrates is quick to point out that the Greek gods were often in conflict with each other, so that what Zeus, for example, would consider to be pious, Hera might not. Euthyphro has allowed his personal beliefs to be transferred to the gods. He has already in his own mind decided what is pious and impious, and held his beliefs as universal because he is a religious man.