Rhythm and melody enter into the soul of the well-instructed youth and produce there a certain mental harmony hardly obtainable in any other way. . . . thus music, too, is concerned with the principles of love in their application to harmony and rhythm.
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.
Thanks to my fortunate idea of introducing the relativity principle into physics, you (and others) now enormously overrate my scientific abilities, to the point where this makes me quite uncomfortable.
Capitalism justified itself and was adopted as an economic principle on the express ground that it provides selfish motives for doing good, and that human beings will do nothing except for selfish motives
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.
it is not necessary to accept everything as true, one must only accept it as necessary.' 'A melancholy conclusion,' said K. 'It turns lying into a universal principle.