When I am attacked by gloomy thoughts, nothing helps me so much as running to my books. They quickly absorb me and banish the clouds from my mind.

Evil being the root of mystery, pain is the root of knowledge.

Opinion is the medium between knowledge and ignorance.

An investment in knowledge pays the best interest.

The ability to observe without evaluating is the highest form of intelligence.

Patience is a virtue, and I'm learning patience. It's a tough lesson.

I decided to teach because I think that any person who studies philosophy has to be involved actively.

Action not backed by knowledge and knowledge not translatable into action, both can not stand the test of time.

The great difficulty in education is to get experience out of ideas.

My alma mater was books, a good library.... I could spend the rest of my life reading, just satisfying my curiosity.

If you're teaching today what you were teaching five years ago, either the field is dead or you are.

The real solution lies in a world in which charity will have become unnecessary.

No man's knowledge here can go beyond his experience.

Real knowledge is to know the extent of one's ignorance.

Liberty without Learning is always in peril and Learning without Liberty is always in vain.

The only good is knowledge and the only evil is ignorance.

Language is courage: the ability to conceive a thought, to speak it, and by doing so to make it true.

Know what you are talking about.

All sciences are vain and full of errors that are not born of Experience, the mother of all Knowledge.

Knowing others is wisdom, knowing yourself is Enlightenment.

God created man in His own image, says the Bible; philosophers reverse the process: they create God in theirs.