When anything is in the presence of evil, but is not as yet evil, the presence of good arouses the desire of good in that thing; but the presence of evil, which makes a thing evil, takes away the desire and friendship of the good; for that which was once both good and evil has now become evil only, and the good has no friendship with evil.
For the introduction of a new kind of music must be shunned as imperiling the whole state; since styles of music are never disturbed without affecting the most important political institutions.
What the expression is intended to mean, I think, is that there is a better and a worse element in the character of each individual, and that when the naturally better element controls the worse then the man is said to be "master of himself", as a term of praise. But when - as a result of bad upbringing or bad company one s better element is overpowered by the numerical superiority of one s worse impulses, then one is criticized for not being master of oneself and for lack of self control.
And among the other honours and rewards our young men can win for distinguished service in war and in other activities, will be more frequent opportunities to sleep with a woman; this will give us a pretext for ensuring that most of our children are born of that parent.
All things will be produced in superior quantity and quality, and with greater ease, when each man works at a single occupation, in accordance with his natural gifts, and at the right moment, without meddling with anything else.
The good are like one another, and friends to one another; and ... the bad, as is often said of them, are never at unity with one another or with themselves, but are passionate and restless: and that which is at variance and enmity with itself is not likely to be in union or harmony with any other thing.