Think as wise men do, but speak as the common people do.

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.

Misfortune shows those who are not really friends.

Actions determine what kind of characteristics are developed.

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.

Fear is pain arising from the anticipation of evil.

When you have thrown a stone, you cannot afterwards bring it back again, but nevertheless you are responsible for having taken up the stone and flung it, for the origin of the act was within you. Similarly the unjust and profligate might at the outset have avoided becoming so, and therefore they are so voluntarily, although when they have become unjust and profligate it is no longer open to them not to be so.