The essence of philosophy is that a man should so live that his happiness shall depend as little as possible on external things.
There is only one way to happiness and that is to cease worrying about things which are beyond the power of our will.
If virtue promises happiness, prosperity and peace, then progress in virtue is progress in each of these for to whatever point the perfection of anything brings us, progress is always an approach toward it.
I must die. Must I then die lamenting? I must be put in chains. Must I then also lament? I must go into exile. Does any man then hinder me from going with smiles and cheerfulness and contentment?
Wealth consists not in having great possessions, but in having few wants.