You will never know how sharp a sword is unless it's drawn from its sheath
Wisdom is rooted in watching with affection the way people grow.
Every truth has four corners: as a teacher I give you one corner, and it is for you to find the other three.
You can cheat an honest man but not make a fool out of him.
Friendship with the upright, with the truthful and with the well informed is beneficial. Friendship with those who flatter, with those who are meek and who compromise with principles, and with those who talk cleverly is harmful.
Wisdom, humanity & courage, these three are universal virtues. The way by which they are practiced are one.