Any change of government which has to be introduced should be one which men, starting from their existing constitutions, will be both willing and able to adopt, since there is quite as much trouble in the reformation of an old constitution as in the establishment of a new one, just as to unlearn is as hard as to learn.
Man perfected by society is the best of all animals; he is the most terrible of all when he lives without law and without justice. If he finds himself an individual who cannot live in society, or who pretends he has need of only his own resources do not consider him as a member of humanity; he is a savage beast or a god.
Now that practical skills have developed enough to provide adequately for material needs, one of these sciences which are not devoted to utilitarian ends [mathematics] has been able to arise in Egypt, the priestly caste there having the leisure necessary for disinterested research.
The things best to know are first principles and causes, but these things are perhaps the most difficult for men to grasp, for they are farthest removed from the senses.
The male has more teeth than the female in mankind, and sheep and goats, and swine. This has not been observed in other animals. Those persons which have the greatest number of teeth are the longest lived; those which have them widely separated, smaller, and more scattered, are generally more short lived.
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.
... the friendship of worthless people has a bad effect (because they take part, unstable as they are, in worthless pursuits, and actually become bad through each other's influence). But the friendship of the good is good, and increases in goodness because of their association. They seem even to become better men by exercising their friendship and improving each other; for the traits that they admire in each other get transferred to themselves.
Persuasion is effected through the medium of the hearers, when they shall have been brought to a state of excitement under the influence of speech; for we do not, when influenced by pain or joy, or partiality or dislike, award our decisions in the same way; about which means of persuasion alone, I declare that the system-mongers of the present day busy themselves.
[I]t is rather the case that we desire something because we believe it to be good than that we believe a thing to be good because we desire it. It is the thought that starts things off.
The society that loses its grip on the past is in danger, for it produces men who know nothing but the present, and who are not aware that life had been, and could be, different from what it is.