If you wish another to keep your secret, first keep it to yourself.
Other Seneca the Younger quotes:
Ignorance is the cause of fear.
No good thing is pleasant to possess, without friends to share it.
Withdraw into yourself, as far as you can. Associate with those who will make a better man of you. Welcome those whom you yourself can improve. The process is mutual; for men learn while they teach.
Familiarity reduces the greatness of things.
The things hardest to bear are sweetest to remember.
There is nothing more despicable than an old man who has no other proof than his age to offer of his having lived long in the world.
Life is long if it is full.
A thing seriously pursued affords true enjoyment.
If you wish to be loved, love.
All things that are still to come lie in uncertainty; live straightway!