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.
When thou art calling out on the Rostra, hast thou forgotten, man, what these things are?- Yes; but they are objects of great concern to these people- wilt thou too then be made a fool for these things?- I was once a fortunate man, but I lost it, I know not how.- But fortunate means that a man has assigned to himself a good fortune: and a good fortune is good disposition of the soul, good emotions, good actions.