...virtue is not merely a state in conformity with the right principle, but one that implies the right principle; and the right principle in moral conduct is prudence.
The history of science can be viewed as the recasting of phenomena that were once thought to be accidents as phenomena that can be understood in terms of fundamental causes and principles.
My interest in science was always essentially limited to the study of principles.... That I have published so little is due to this same circumstance, as the great need to grasp principles has caused me to spend most of my time on fruitless pursuits.
Be sincere and true to your word, serious and careful in your actions; and you will get along even among barbarians, But if you are not sincere and untrustworthy in your speech, frivolous and careless in your actions, how will you get along even among your own neighbors? When stand, see these principles in front of you; in your carriage see them on the yoke. Then you may be sure to get along.