What did you do today to receive your instruction?

Preconceived ideas are like searchlights which illumine the path of the experimenter and serve him as a guide to interrogate nature. They become a danger only if he transforms them into fixed ideas-this is why I should like to see these profound words inscribed on the threshold of all the temples of science: 'The greatest derangement of the mind is to believe in something because one wishes it to be so.'

There is a time in every man's life when he looks to his God, when he looks at his life, when he wonders how he will be remembered.

The Greeks understood the mysterious power of the below things. They are the ones who gave us one of the most beautiful words in our language, the word enthusiasm.

As in the experimental sciences, truth cannot be distinguished from error as long as firm principles have not been established through the rigorous observation of facts.

Inspiration is the impact of a fact on a well-prepared mind

The more I know, the more nearly is my faith that of the Breton peasant. Could I but know all I would have the faith of a Breton peasant woman.