Learning without thought is labor lost; thought without learning is perilous.

The benefits of knowledge can only be realized in practice.

Prefer knowledge to wealth, for the one is transitory, the other perpetual.

A teacher can never truly teach unless he is still learning himself. The teacher who has come to the end of his subject, who has no living traffic with his knowledge but merely repeats his lesson to his students, can only load their minds, he cannot quicken them.

Learning is the only thing the mind never exhausts, never fears, and never regrets.

Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.