This is one of my favorite Socratic dialogues. Socrates really lays into Euthyphro and shows what a sarcastic old guy he was. Most dialogues can be read on their own, but this one is helped by a little basic knowledge of the ancient Greek mythology. In it, Socrates and the eponymous interlocutor discuss the nature of holy and, by implication, the nature of other such indefinable concepts like good, evil, piety, love, etc. This is the basis, if I remember correctly, for the whole monad theme. There is a certain quality about anything that gives that thing its unique identity. Such that a tree has a certain tree-ness to it that, regardless of language, makes it a tree no matter the perceiver. Modern philosophy really loves this whole theme.
I guess that my question pertains to the relevance of this dialogue in our current society. Can this dialogue be applied to a society with one god that is all good? I don't personally believe in God as others do but I wonder about the nature of holiness. Holy is an attribute of a thing. I would say that to be holy is to have some aspect of the divine. However, that would probably all depend on the perceiver. For instance, every now and then a tortilla will pop up with a smudge that looks remarkably like the face of the Virgin Mary or Jesus or whomever. Is this tortilla holy? I guess my definition would declare it holy if someone claims that the tortilla has an aspect of the divine. Some part of God is perhaps easier to perceive in the Mary tortilla than in a plain tortilla. This definition is falling into the same trap as Euthyphro's first. I can only declare that certain things are holy while giving no definition of the concept. It may be easier to say that to be holy is have some aspect of the divine but that leads to the question, what is divinity? Following even further, what is the nature of god and how do we find these aspects in our world? Even in monotheistic cultures such as ours, we all struggle with varying definitions of God, good, piety and holiness. I love this dialogue because you can just keep thinking about it and because this question can be asked of almost anyone.
I think Euthyphro would make a great short movie.
As a final bit, people who claim that philosophy has little or no bearing on real life should read this dialogue. There is a section about going to an expert in times of uncertainty. I personally follow this advice all the time. When I am approaching a task I know nothing about, I imagine a man in my mind who has far greater knowledge on the subject and I ask myself, what would he do? It usually works out pretty well.