The only true wisdom is in knowing you know nothing.

There is only one good, knowledge, and one evil, ignorance.

The more I see, the less I know for sure.

Time stays long enough for anyone who will use it.

The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.

The most important knowledge is that which guides the way you lead your life.

I have been impressed with the urgency of doing. Knowing is not enough, we must apply. Being willing is not enough, we must do.

If you can't explain it to a six year old, you don't understand it yourself.

The noblest pleasure is the joy of understanding.