Despite the fact that no clear answer is produced in the dialogue between Socrates and Euthyphro regarding how to define "the pious" (to hoison), it seems like it's a mistake to say that no progress was made.  In fact, shortly before Euthyphro rushes off and ends the conversation, Socrates himself says that they are on the verge of finding what it is that he wants to know.  It seems like the biggest stumbling block to revealing what "piety" is all about is Euthyphro's unwillingness to admit that he didn't really know what he thought he did.  Perhaps this is why he runs off as he does.  

In light of all of this, and what you have learned about piety from this dialogue, tell whether you think that Euthyphro's decision to prosecute his father for murder is the pious thing to do.  If so, why?  If not, what would the pious action in this case be?

Defining piety is the central theme of Euthyphro, and (by Socratic standards at least) this proves to be difficult. Socrates was not an easy person to convince. As we will read in his Apology, he often made the various "wise" men he questioned indignant (he pissed them off)... because he kept prying for deeper and clearer meaning of whatever was the subject at hand. I don't think many people could hold their own against such relentless scrutiny. Euthyphro begs off after being picked apart several times. I can't say that I blame him...

     While I admire the Socratic method, as it's called- I would venture that there comes a point where you have to back off; you can't keep "peeling the onion" forever. There is a phenomenon called "semantic satiation"- it's the continued repetition of a word or phrase until it becomes temporarily meaningless. Most of us have experienced that. And I think it is similar to what is going on between Socrates and Euthyphro: the latter has been asked to reevaluate his statements to the point of apathy; he doesn't care to pursue it any further.

    I'm going to take the potentially controversial stance that Euthyphro was being pious. Let's look at some modern definitions:

from Dictionary.com: "characterized by a hypocritical concern with virtue or religious devotion; sanctimonious."

Cambridge English dictionary: "strongly believing in a religion."

    To be "pious" doesn't mean that one is morally or ethically right- it simply means that they are somewhat zealous about what they believe, for better or worse. I could be pious in a belief that eugenics is the best plan for the human race. That wouldn't make me right about that; it's what Hitler believed.

     Euthyphro believed that he was doing the right thing by the gods in prosecuting his own father. (It's a tricky matter to say that his father committed murder, I agree. It sounds more like criminal negligence). But if Euthyphro truly believed that his father had broken the law and offended the gods, I say that it is an act of piety to stay true to his convictions.

     What Socrates accomplished was showing Euthyphro how shaky those convictions were. And that is one of the hallmarks of philosophy, to which we owe Socrates and his successors a great debt- we must question everything.