"Ευθύφρων" by Plato is a philosophical dialogue written around 399 BC. Set before Socrates' trial for impiety, the work follows his encounter with Euthyphro, a prophet prosecuting his own father for murder. Socrates asks Euthyphro to define piety, leading to a famous philosophical problem: do the gods love what is pious because it is pious, or is something pious because the gods love it? Their debate reaches no clear conclusion, sparking centuries of theological and ethical discussion.