To see others suffer does one good, to make others suffer even more: this is a hard saying but an ancient, mighty, human, all-too-human principle [....] Without cruelty there is no festival.
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.
[the virtues] cannot exist without Prudence. A proof of this is that everyone, even at the present day, in defining Virtue, after saying what disposition it is [i.e. moral virtue] and specifying the things with which it is concerned, adds that it is a disposition determined by the right principle; and the right principle is the principle determined by Prudence.
Once you become aware of your own body and its movements, you will be surprised that you are not your body. This is something of a basic principle, that if you can watch something then you are not it. You are the watcher, not the watched. You are the observer, not the observed. How can you be both?
The fourfold root of the principle of sufficent reason is "Anything perceived has a cause. All conclusions have premises. All effects have causes. All actions have motives.
Softness triumphs over hardness, feebleness over strength. What is more malleable is always superior over that which is immoveable. This is the principle of controlling things by going along with them, of mastery through adaptation.