About this passageA rehearsal, given as a method rather than an argument. Epictetus takes the most ordinary errand he can think of — going to the public baths, which in Rome meant crowds, shoving and petty theft — and has the reader run through what will go wrong before setting out. The second half is the part that does the work: the intention is stated twice, once as the errand and once as the thing that cannot be taken from you, so that the errand failing does not take the day with it.
When you set about any action, remind yourself of what nature the action is. If you are going to bathe, represent to yourself the incidents usual in the bath—some persons pouring out, others pushing in, others scolding, others pilfering. And thus you will more safely go about this action if you say to yourself, "I will now go to bathe and keep my own will in harmony with nature." And so with regard to every other action. For thus, if any impediment arises in bathing, you will be able to say, "It was not only to bathe that I desired, but to keep my will in harmony with nature; and I shall not keep it thus if I am out of humor at things that happen."
In plainer words
Before you do anything, say what kind of thing it is. Going to the baths? Then picture it properly: people splashing, people shoving in, someone shouting, someone going through the lockers. Set out saying two things — I am going to bathe, and I am going to keep my own conduct as it should be. Then if the bathing goes badly you still have the second one, and you have not lost your temper over the part that was never yours to arrange.
A restatement in modern English, written for this collection. The passage above is the text; this is one way of putting it.