Summary:
Epictetus explains that just as a doctor works with the body and a farmer with the land, the philosopher or virtuous person works on their own mind and reasoning. Your character and thinking are the raw materials you must continually refine and develop.
Interpretation:
In everyday life, this means recognising that self-improvement is your primary responsibility. Instead of trying to control others or external events, focus on shaping your own thoughts, behaviours, and values. Just as a craftsman hones his tools, you must treat your inner life as your most important work—learning, reflecting, and acting in ways that strengthen your character over time.