What the statesman is most anxious to produce is a certain moral character in his fellow citizens, namely a disposition to virtue and the performance of virtuous actions.
If then, as we say, good craftsmen look to the mean as they work, and if virtue, like nature, is more accurate and better than any form of art, it will follow that virtue has the quality of hitting the mean. I refer to moral virtue [not intellectual], for this is concerned with emotions and actions, in which one can have excess or deficiency or a due mean.
Thus it is thought that justice is equality; and so it is, but not for all persons, only for those that are equal. Inequality also is thought to be just; and so it is, but not for all, only for the unequal. We make bad mistakes if we neglect this for whom when we are deciding what is just. The reason is that we are making judgements about ourselves, and people are generally bad judges where their own interests are involved.
It is clear, then, that the earth must be at the centre and immovable, not only for the reasons already given, but also because heavy bodies forcibly thrown quite straight upward return to the point from which they started, even if they are thrown to an infinite distance. From these considerations then it is clear that the earth does not move and does not lie elsewhere than at the centre.
Music directly imitates the passions or states of the soul...when one listens to music that imitates a certain passion, he becomes imbued withthe same passion; and if over a long time he habitually listens to music that rouses ignoble passions, his whole character will be shaped to an ignoble form.
For contemplation is both the highest form of activity (since the intellect is the highest thing in us, and the objects that it apprehends are the highest things that can be known), and also it is the most continuous, because we are more capable of continuous contemplation than we are of any practical activity.
Of actions some aim at what is necessary and useful, and some at what is honorable. And the preference given to one or the other class of actions must necessarily be like the preference given to one or other part of the soul and its actions over the other; there must be war for the sake of peace, business for the sake of leisure, things useful and necessary for the sake of things honorable.