He has reached the supreme good who is never sad, or excited by hope, but keeps an even and happy frame of mind by day and night.
Seneca's Epistles, lix, sec. 14
The wise man's joy is woven so well as not to be broken by any accident.
Seneca's Epistles, lxxii, sec. 4
Fortune has not such long arms as we think; she seizes on no one who is not clinging to her.
Seneca's Epistles lxxxii, sec. 5