The greatest virtues are those which are most useful to other persons.

You are what you do repeatedly.

This much then, is clear: in all our conduct it is the mean that is to be commended.

There is only one condition in which we can imagine managers not needing subordinates, and masters not needing slaves. This condition would be that each (inanimate) instrument could do its own work.

When you are lonely, when you feel yourself an alien in the world, play Chess. This will raise your spirits and be your counselor in war

...in this way the structure of the universe- I mean, of the heavens and the earth and the whole world- was arranged by one harmony through the blending of the most opposite principles.

Great men are always of a nature originally melancholy.