Socrates and Meno (and Anytus, who is largely silent from here on) have now concluded that virtue is at least partly a kind of wisdom, but that even the most beneficent men are not virtuous only out of knowledge (as evidenced by the fact that none of them seem capable of teaching it). This last point, suggests Socrates, is one reason why he and Meno may have failed to find virtue itself in considering such virtuous men. This suggestion puzzles Meno, and Socrates explains that, while they had been looking for virtue as a kind of teachable knowledge, virtuous men's good deeds could equally well be the result not of knowledge but of "true opinion."
Socrates gives the example of a guide on the road to Larissa: whether the guide has knowledge of the way or a true opinion about the way, the result is the same (a successful trip to Larissa). But if this is the case, asks Meno, "why is knowledge prized far more highly than right opinion, and why are they different?"
Socrates' answer gives the metaphor of a man who possesses a valuable sculpture by Daedalus. If the statue is "tied down," it is of lasting value. If, however, it is not tied down, it won't last long and is therefore of less good. Similarly, true opinions "are not willing to remain long, and they escape from a man's mind, so that they are not worth much until one ties them down by giving "an account of the reason why" the opinion is true [my italics]. Such an account allows true opinion to become knowledge through the process of "recollection" discussed earlier, and so to become fixed in the mind. Nonetheless, at least in terms of directing actions at given times, true opinion serves as well as knowledge.
Socrates and Meno now face a final problem: they have concluded both that virtue cannot be taught and that it is not innate (both parties agree that neither knowledge nor true opinion can be innate). So, returning to the question that opened the dialogue, how do men become virtuous? Plato (through Socrates) is content to leave this a mystery of sorts for now, concluding only that virtuous statesmen are only so through a sort of divine inspiration, like "soothsayers and prophets. They too say many true things when inspired, but they have no knowledge of what they are saying" [my italics].
Thus, virtue is left as "a gift from the gods which is not accompanied by understanding." Though this deep uncertainty may not seem like much of an end to the dialogue, the apparent emptiness of Socrates' conclusion is mitigated by the importance of the lack of knowledge in and of itself. Socrates has succeeded in convincing two prominent citizens and men of politics not only that they have no understanding of virtue, but also that no one does. This state of uncertainty, or aporia, the state of knowing that one does not know, is a major Platonic theme, and clears the ground for the pursuit of a kind of truth far more exacting and rigorous than had been previously sought.
The Meno ends as Socrates bids his interlocutors farewell, reminding them once more that they must seek to know what virtue is (and, according to him, they'd be the first to truly know) before finding out how it comes to be in men. Departing, Socrates tells Meno to teach Anytus what he has learned today.