"We need prudence or practical wisdom for any large-scale worthy enterprise, just as health and sanity are needed. We need justice to secure cooperation and mutual trust… without which our lives would be nasty, brutish, and short. We need temperance in order not to be deflected from our long-term and large-scale goals by seeking short-term satisfactions. And we need courage in order to persevere in the face of setbacks, weariness, difficulties, and dangers."