“Choose the life that is most useful, and habit will make it the most agreeable.”

“Some books should be tasted, some devoured, but only a few should be chewed and digested thoroughly.”

“God has, in fact, written two books, not just one. Of course, we are all familiar with the first book he wrote, namely Scripture. But he has written a second book called creation.”

“Books speak plain when counselors blanch.”

“We have only this moment, sparkling like a star in our hand and melting like a snowflake...”

“Nature is often hidden, sometimes overcome, seldom extinguished.”

“Quien no quiere pensar es un fanático; quien no puede pensar es un idiota; quien no osa pensar es un cobarde.”