From Discourses and Enchiridion:

 

... let this be your study and constant pursuit, to learn in what it is necessary to be courageous, and in what cautious; courageous against the inevitable, cautious so far as your will can control events.

 

Every habit and faculty is preserved and increased by the corresponding actions; as the habit of walking, by walking; of running, by running. If you would be a reader, read; if a writer, write.

 

Books by Epictetus at Powell's Books