The knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes.

Silence is the sleep that nourishes wisdom.

Have patience. All things are difficult before they become easy.

It is harder to conceal ignorance than to acquire knowledge.

The possession of knowledge does not kill the sense of wonder and mystery. There is always more mystery.

Cherish that which is within you, and shut off that which is without; for much knowledge is a curse.

An effort made for the happiness of others lifts above ourselves.

It is amazing what you can accomplish if you do not care who gets the credit.

If you do not think about your future, you cannot have one.

Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning.