The dialogue takes place outside the porch of the King Archon, where Socrates is awaiting his impending trial for impiety brought by Meletus. There he encounters Euthyphro, a self-assured soothsayer who is currently prosecuting his own father for the accidental homicide of a laborer. Recognizing Euthyphro's professed expertise in matters of religion, Socrates asks him to define piety and impiety so that he might learn how to defend himself against the charges of corrupting the youth and inventing new deities.
Euthyphro first defines piety as prosecuting wrongdoers, citing the mythological example of Zeus binding his own father. Socrates rejects this answer, demanding a universal definition or standard rather than mere examples. Euthyphro then suggests that the pious is simply what is dear to the gods. Socrates points out that the gods often quarrel over matters of justice and goodness, meaning the same thing can be both loved and hated by the divine.
Seeking a more refined answer, they amend the definition to state that the pious is what all the gods love. Socrates subjects this proposition to logical scrutiny, asking whether the holy is loved by the gods because it is holy, or holy because it is loved. Through this dilemma, he demonstrates that being loved is merely an attribute of piety rather than its essential nature, causing their arguments to move in circles.
Desperate for a resolution, Socrates attempts to guide Euthyphro toward placing religion on a moral foundation by suggesting that piety is a part of justice. Euthyphro proposes that piety is the specific part of justice concerned with attending to the gods, comparing it to the service a servant offers a master. When pressed to explain what benefit this ministration brings to the gods, Euthyphro retreats to the notion that piety involves knowing how to please the gods through prayer and sacrifice.
This final attempt reduces piety to a commercial exchange of giving and asking between gods and men, bringing the conversation right back to where it started. Socrates patiently points out that their conclusions continue to slip away because Euthyphro refuses to follow the argument to its proper end. When Socrates urges him to continue the examination and reveal the true essence of holiness, Euthyphro abruptly pleads that he is in a hurry and leaves, abandoning Socrates to face his trial alone.
