Whatever we learn to do, we learn by actually doing it; men come to be builders, for instance, by building, and harp players by playing the harp. In the same way, by doing just acts we come to be just; by doing self-controlled acts, we come to be self-controlled ; and by doing brave acts, we become brave.

He who is unable to live in society, or who has no need because he is sufficient for himself, must be either a beast or a god.

Thus then a single harmony orders the composition of the whole...by the mingling of the most contrary principles.

The truly good and wise man will bear all kinds of fortune in a seemly way, and will always act in the noblest manner that the circumstances allow.

The man who is truly good and wise will bear with dignity whatever fortune sends, and will always make the best of his circumstances.

No one would choose a friendless existence on condition of having all the other things in the world.

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.