Men must be able to engage in business and go to war, but leisure and peace are better; they must do what is necessary and indeed what is useful, but what is honorable is better. On such principles children and persons of every age which requires education should be trained.
In cases of this sort, let us say adultery, rightness and wrongness do not depend on committing it with the right woman at the right time and in the right manner, but the mere fact of committing such action at all is to do wrong.
Demonstration is also something necessary, because a demonstration cannot go otherwise than it does, ... And the cause of this lies with the primary premises/principles.
Salt water when it turns into vapour becomes sweet, and the vapour does not form salt water when it condenses again. This I know by experiment. The same thing is true in every case of the kind: wine and all fluids that evaporate and condense back into a liquid state become water. They all are water modified by a certain admixture, the nature of which determines their flavour.
Emotions of any kind are produced by melody and rhythm; therefore by music a man becomes accustomed to feeling the right emotions; music has thus the power to form character, and the various kinds of music based on various modes may be distinguished by their effects on character.
... the good for man is an activity of the soul in accordance with virtue, or if there are more kinds of virtue than one, in accordance with the best and most perfect kind.
What is the highest of all goods achievable by action? ...both the general run of man and people of superior refinement say that it is happiness ...but with regard to what happiness is they differ.