From the Philosophy of Socrates: Meno by Plato, Part 2 of 2

Meno: Well then, courage, I consider, is a virtue, and temperance, and wisdom, and loftiness of mind; and there are a great many others. Socrates: Once more, Meno, we are in the same plight: again we have found a number of virtues when we were looking for one, though not in the same way as we did just now; but the one that runs through them all, this we are not able to find.