These traits they called virtues. In other words, virtues are needed for human beings to conduct their lives well.
Moral virtue is a mean between two extremes, the one involving excess and the other deficiency.
To use Aristotle's method, begin by identifying extremes and then seek a balance between the two. For those prone to one extreme, the balance comes from leaning toward the other extreme. The farther away you are, the more you must lean. Good character can lead to good actions. There is no simple way to determine right action.