There is none who cannot teach somebody something, and there is none so excellent but he is excelled.
True knowledge lies in knowing how to live.
Knowledge without courage is sterile.
Do not show your wounded finger for everything will knock up against it.
The wise persono would rather see others needing him than thanking him.
It takes more to make one sage today than it did to make the seven of Greece. And you need more resources to deal with a single person these days than with an entire nation in times past.