An investment in knowledge pays the best interest.

Knowledge is power only if man knows what facts not to bother with.

Learning never exhausts the mind.

The first step towards knowledge is to know that we are ignorant.

The larger the island of knowledge, the longer the shoreline of wonder.

Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.

The true method of knowledge is an experiment.

To know is to know that you know nothing. That is the meaning of true knowledge.

Knowledge is the life of the mind.

A single conversation across the table with a wise man is better than ten years' of mere study of books.