All men, or most men, wish what is noble but choose what is profitable; and while it is noble to render a service not with an eye to receiving one in return, it is profitable to receive one. One ought therefore, if one can, to return the equivalent of services received, and to do so willingly; for one ought not to make a man one's friend if one is unwilling to return his favors.
For legislators make the citizens good by forming habits in them, and this is the wish of every legislator, and those who do not effect it miss their mark, and it is in this that a good constitution differs from a bad one.
Rhetoric is useful because truth and justice are in their nature stronger than their opposites; so that if decisions be made, not in conformity to the rule of propriety, it must have been that they have been got the better of through fault of the advocates themselves: and this is deserving reprehension.
The soul is the cause or source of the living body. The terms cause and source have many senses. But the soul is the cause of its body alike in all three senses which we explicitly recognize. It is (a) the source or origin of movement, it is (b) the end, it is (c) the essence of the whole living body.
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.