50 AD for a somewhat relevant post... that's going to be tough to beat.
It is better to create than to learn! Creating is the essence of life.
It is not these well-fed long-haired men that I fear, but the pale and the hungry-looking.
As a rule, men worry more about what they can't see than about what they can.
Cowards die many times before their actual deaths.
and that's between 100BC and 44BC
"Cowards die many times before their deaths. The valiant never taste of death but once." - William Shakespeare, Julius Caesar, Act II, sc. ii (1599)
Edit: Human history is full of interesting "posts". If only we had the time to absorb all the wisdoms of times passed.
If you like the Art of War at all, you simply must read von Clauswitz's On War:
http://en.wikipedia.org/wiki/On_War#Synopsis
At least read the first 20 pages. An incredibly clear, insightful thinker. He was an utter perfectionist, he worked on the book for decades and died with it incomplete, but the beginning in particular is precisely accurate and insightful like almost nothing else I've read.