Better mad with the rest of the world than wise alone.
Advice is sometimes transmitted more successfully through a joke than through grave teaching.
If you can't make knowledge your servant, make it your friend.
Don't express your ideas too clearly. Most people think little of what they understand, and venerate what they do not.
At 20 a man is a peacock, at 30 a lion, at 40 a camel, at 50 a serpent, at 60 a dog, at 70 an ape, and at 80 nothing.
Wisdom does not trust to probabilities; it always marches in the midday light of reason.
A wise man gets more use from his enemies than a fool from his friends.