From Seneca’s letters and essays

On Adversity

“You are a great man, but how can I know if Fortune has never given you a chance to display your prowess? For self-knowledge testing is necessary; no one can discover what he can do except by trying.  I account you unfortunate because you have never been unfortunate.”

On Moderation:

“All excesses are injurious.”

On Seizing the Day:

“How much of your life has been pilfered by others, how much of it you have lost, or dispensed on groundless regret, greedy desire, foolish gladness, polite society—only then will your death seem premature.  Why should this be? It is because you live as if you would live forever; the thought of human frailty never enters your mind.  You squander it as though your store were full to overflowing when in fact the very day of which you make a present to someone else may be your last.”

On the Shortcomings of Pleasure:

“All very great blessings involve anxiety; good fortune is less to be trusted than any other.  To preserve felicity new felicity is needed.  Anything that comes by chance is unstable, and the higher it rises the more liable it is to fall.”

On Hoping:

“When men dare not or cannot attain as much as they crave and rest wholly on hopes, they are unstable and vacillating, as is inevitable for persons in suspense.”

“Expectancy is the greatest impediment to living. In anticipation of tomorrow it loses today. Everything future is uncertain.”