When Epictetus advises us to want events “to happen as they do happen,” he is giving us advice regarding events that do happen—that either have happened or are happening—not advice regarding events that will happen. He is, in other words, advising us to behave fatalistically with respect to the past and present. Likewise, just as you cannot welcome a visitor until he arrives, Marcus’s good man cannot welcome the experiences the looms of fate weave for him until those experiences have arrived.
