The precepts of the law may be comprehended under these three points: to live honestly, to hurt no man willfully, and to render every man his due carefully.
A young man is not a proper hearer of lectures on political science; for he is inexperienced in the actions that occur in life, but its discussions start from these and are about these; and, further, since he tends to follow his passions, his study will be vain and unprofitable, because the end that is aimed at is not knowledge but action. And it makes no difference whether he is young in years or youthful in character.
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.
It is the activity of the intellect that constitutes complete human happiness - provided it be granted a complete span of life, for nothing that belongs to happiness can be incomplete.
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.
There are, then, three states of mind ... two vices--that of excess, and that of defect; and one virtue--the mean; and all these are in a certain sense opposed to one another; for the extremes are not only opposed to the mean, but also to one another; and the mean is opposed to the extremes.