How does Epictetus use the metaphor of an actor in a drama to describe our role in life?

The image comes from a single short passage. Epictetus tells you to remember that you are an actor in a drama, of such a kind as the author pleases to make it, whether short or long, and whether the part given you is a poor man, a cripple, a governor, or a private person (Handbook 17). Your job is to act it naturally. The casting is not yours to choose.

The line that carries the whole point is the last one: this is your business, to act well the character assigned you, to choose it is another's (Handbook 17). Read quickly, this can sound like advice to accept your station in life and stop complaining, a kind of resignation dressed up as philosophy. That is the common misreading, and it misses what Epictetus is actually dividing.

He is not telling you that your social role is fixed or that ambition is wrong. He is applying the distinction he opens the Handbook with, between what is in our control and what is not (Handbook 1). Your circumstances, your body, your reputation, your position in the world, all belong to the category of things not in our control, things that are, as he puts it, weak, slavish, restrained, belonging to others (Handbook 1). The part you are handed, rich or poor, healthy or sick, powerful or obscure, falls on that side of the line. But how you play the part, whether you act it with honesty, self-command, and care, belongs entirely to you. That is your one true possession.

Epictetus makes the same point through a different image in the Discourses, where he has Zeus explain why we were given only this one faculty as fully our own. Zeus tells Epictetus that he could not make the body or property free from hindrance, so he gave him instead a small portion of himself: the faculty of pursuing and avoiding, of desire and aversion, the faculty of using impressions well. Zeus adds that if you take care of this faculty and consider it your only possession, you will never be hindered, never meet with impediments, and you will not lament, blame, or flatter anyone (Discourses I.1). The actor's script is the same lesson in a different key. The part is given. The acting is yours.

This changes what you're actually striving for. If you think your job is to get the good part, you will spend your life resenting the casting and envying other actors, the ones who got to play the governor while you got the cripple. Epictetus's claim is more radical than accept your lot: it says your lot, in the sense of health, wealth, and standing, was never the kind of thing that could be good or bad for you in the first place. Only your own choices carry that weight. A person who plays a hard part with honesty and steadiness has succeeded completely, on Epictetus's terms, even if the play itself never rewards it.

None of this means you should be passive about your circumstances. Elsewhere Epictetus is clear that you can pursue preferred things and avoid dispreferred ones using the same faculty of choice he says is fully yours. The actor metaphor is about where your evaluation belongs, not about refusing to try to change your role within the ordinary limits of what is up to you.

One concrete way to use this: the next time you find yourself resenting a circumstance you did not choose, a diagnosis, a demotion, a difficult family, ask a narrower question than is this fair. Ask whether you are acting the part well, whatever it is.