Often think of the rapidity with which things pass by and disappear, both the things which are and the things which are produced. For substance is like a river in a continual flow, and the activities of things are in constant change, and the causes work in infinite varieties; and there is hardly anything which stands still. And consider this which is near to thee, this boundless abyss of the past and of the future in which all things disappear. How then is he not a fool who is puffed up with such things or plagued about them and makes himself miserable? for they vex him only for a time, and a short time.
Let not future things disturb thee, for thou wilt come to them, if it shall be necessary, having with thee the same reason which now thou usest for present things.
Constantly consider how all things such as they now are, in time past also were; and consider that they will be the same again. And place before thy eyes entire dramas and stages of the same form, whatever thou hast learned from thy experience or from older history; for example, the whole court of Hadrian, and the whole court of Antoninus, and the whole court of Philip, Alexander, Croesus; for all those were such dramas as we see now, only with different actors.