The most useful piece of learning for the uses of life is to unlearn what is untrue.
The most necessary learning is that which unlearns evil.
The investigation of the meaning of words is the beginning of education.
How to get rid of having anything to unlearn.
When brothers agree, no fortress is so strong as their common life.
There are only two people who can tell you the truth about yourself - an enemy who has lost his temper and a friend who loves you dearly.