 To say that such a person “sees” what to do is simply a way of registering the point that the good person’s reasoning does succeed in discovering what is best in each situation. He is “as it were a standard and measure” in the sense that his views should be regarded as authoritative by other members of the community. A standard or measure is something that settles disputes; and because good people are so skilled at discovering the mean in difficult cases, their advice must be sought and heeded.