THE ENCHIRIDION Ch. 17 (source: Project Gutenberg)
Remember that you are an actor in a drama of such sort as the Author chooses—if short, then in a short one; if long, then in a long one. If it be his pleasure that you should enact a poor man, or a cripple, or a ruler, or a private citizen, see that you act it well. For this is your business—to act well the given part, but to choose it belongs to another.