John Holbo replies gently here and here to my disagreement with his assertion that the Euthyphro “concludes inconclusively.” Holbo — more learned in these matters than I — reads the dialogue as being mostly about ignorant certitude and the difficulty of persuading those who don’t notice, or don’t care, that one of their strongly-held beliefs has just been demolished. I think he’s right to find that theme a central one, but that reading can, it seems to me, coexist comfortably with the stress I placed on the problem of criticizing what one reveres, ought to revere.
Holbo makes a good case that what he calls the “Euthyphro syndrome” is a central political problem, what with all the promiscuous believing that runs around the political sphere, and especially blogspace. [The definition of “philosopher” that makes sense of the idea that “philosophers” should rule is “One who would rather change his opinion than remain wrong.” A characteristic failing of intellectuals thinking about politics is forgetting that the philosophic temperament in that sense is rare, and that not being a philosopher in that sense — cheerfully holding nonsensical, false-to-fact, and even contradictory opinions — is the normal human condition, and not a sign of intellectual deficiency. More on that thought here.]
He carries the point uncomfortably close to home: “The vice of punditry,” says Holbo, “is willingness to pronounce with unfeigned confidence on matters one is clearly strictly incompetent to judge.” Ouch! He got me! My post was very blog-like in expressing a stronger opinion than my qualifications justify. (I’m a policy analyst by trade, not a philosopher, and I can’t even read Greek.)
Holbo argues that persuading the unpersuadable provides a thematic link between Euthyphro to Meno and the very beginning of Republic I, and calls that theme “a red thread” through the Platonic labyrinth. (I think the same thread runs through the discussion about rhetoric and medicine in the Gorgias, where the problem is the persuasion of the ignorant, and the rhetor turns out to be the necessary auxiliary of the philosopher: if it’s true that the true physician is unable to persuade the patient to take his medicine, then the physician’s art is incomplete and needs the art of persuasion to make it capable of achieving its ends.)
Still, I think (under correction) that the dialogue concludes only that Euthyphro doesn’t know what piety is, and that the attentive reader can get a fairly clear idea of the correct definition by examining each of Euthyphro’s four attempts (what I’m doing now, what’s pleasing to the gods, knowledge of prayer and sacrifice, and the part of justice regarding the divine) to see what it contributes and what it lacks. But for a “soundbite” answer, a sort of mnemonic for the full complexity that can’t be expressed adequately in propositions, I think “the part of justice regarding things superior to, and beneficent towards, oneself” turns out to work pretty well.
As to Socrates’s statement that Euthyphro must know what piety is if anyone knows, it’s not a bare assertion, but a conclusion from the implicit premise that Euthyphro’s action is a right action. If it is, he must be the world’s greatest expert on piety, since everyone else will think it impious to prosecute one’s father on a capital charge. Clearly, the follow-on assertion — that if Euthyphro would just stay and educate Socrates then Socrates would be able to acquit himself of Meletus’s indictment — isn’t literally true. So I’m not inclined to take the assertion “Euthyphro knows, if anyone knows” literally rather than ironically.
One possible reading of the whole: Euthyphro, in prosecuting his father, is attempting the most difficult sort of pious act. If Socrates had full knowledge of how to bring off such an act — which would include the knowledge of how to persuade others that he was right — he could indeed escape Meletus’s indictment. The dialogue shows that Euthyphro has no clear idea what he is doing, and (as Holbo points out) isn’t really interested in learning. But it doesn’t show that no knowledge is available, though Socrates’s fate suggests that perfect knowledge, in this area as in others, is not available to humans.
Maybe the Euthyphro-if-anyone claim means something like “Only those who are willing to criticize what they revere can ever achieve any knowledge of piety in its most profound sense, but those most willing to criticize tend to be unserious: profoundly, as well as superficially, irreverent.”