If what was said in the Ethics is true, that the happy life is the life according to virtue lived without impediment, and that virtue is a mean, then the life which is in a mean, and in a mean attainable by every one, must be the best. And the same principles of virtue and vice are characteristic of cities and of constitutions; for the constitution is in a figure the life of the city.
There is an error common to both oligarchies and to democracies: in the latter the demagogues, when the multitude are above the law, are always cutting the city in two by quarrels with the rich, whereas they should always profess to be maintaining their cause; just as in oligarchies the oligarchs should profess to maintain the cause of the people, . .
If every tool, when ordered, or even of its own accord, could do the work that befits it... then there would be no need either of apprentices for the master workers or of slaves for the lords.
...we are all inclined to ... direct our inquiry not by the matter itself, but by the views of our opponents; and, even when interrogating oneself, one pushes the inquiry only to the point at which one can no longer offer any opposition. Hence a good inquirer will be one who is ready in bringing forward the objections proper to the genus, and that he will be when he has gained an understanding of the differences.
In the human species at all events there is a great diversity of pleasures. The same things delight some men and annoy others, and things painful and disgusting to some are pleasant and attractive to others.
Special care should be taken of the health of the inhabitants, which will depend chiefly on the healthiness of the locality and of the quarter to which they are exposed, and secondly on the use of pure water; this latter point is by no means a secondary consideration. For the elements which we use the most and oftenest for the support of the body contribute most to health, and among those are water and air. Wherefore, in all wise states, if there is want of pure water, and the supply is not all equally good, the drinking water ought to be separated from that which is used for other purposes.
Hence both women and children must be educated with an eye to the constitution, if indeed it makes any difference to the virtue of a city-state that its children be virtuous, and its women too. And it must make a difference, since half the free population are women, and from children come those who participate in the constitution.