There is one word which may serve as a rule of practice for all one's life -reciprocity.
Who keeps the old akindle and adds new knowledge is fitted to be a teacher.
As the water shapes itself to the vessel that contains it, so a wise man adapts himself to circumstances.
Everyone calls his son his son, whether he has talents or has not talents.
Study as though you cannot catch up to it, and as though you fear you are going to lose it.
I will not be concerned at other men's not knowing me;I will be concerned at my own want of ability.