Living a Principle-Centered Life
The art of living is not found in logic, nor in wealth, fame, or in any indulgence. Where is it then? In doing what human nature demands.
How is a person to do this? By having principles be the source of desire and action. What principles? Those to do with good and evil, indeed in the belief that there is no good for a human being except what creates justice, self-control, courage and freedom, and nothing evil except what destroys these things.
Marcus Aurelius, from Meditations
The Daily Stoic: 366 Meditations on Wisdom, Perseverance, and the Art of Living
Background on Marcus Aurelius