Euthyphro

Euthyphro is a philosophic dialogue by Plato exemplifies the style of questioning practiced by Socrates, the principle character. 

The text takes the form of a long conversation between Socrates and the titular Euthyphro, in which they discuss the meaning of piety - or holiness. At the time, Socrates was awaiting trial to face a charge of impiety levied against him by the local government. The two hold their conversation close to the courts of Athens, as the preliminary proceedings for the trial are underway. 

In the text, the textbook Socratic method is used, whereby Socrates himself pretends to possess no knowledge and asks a series of questions naively of his conversation partner, whom he deems experienced and knowledgeable. Gradually the two assemble an argument as to what piety is, and how a person might become pious or impious.  

Weeks after this dialogue is supposed to have taken place, Socrates was found guilty of impiety and sentenced to death, making the dialogue particularly poignant in the context of Plato and his contemporary philosophers in Greece.