Little science takes you away from God but more of it takes you to Him.

If science has no country, the scientist should have one, and ascribe to it the influence which his works may have in this world.

Whatever your career may be, do not let yourselves become tainted by a deprecating and barren scepticism.

The greatest derangement of the mind is to believe in something because one wishes it to be so.

Virulence appears in a new light which cannot but be alarming to humanity; unless nature, in her evolution down the ages (an evolution which, as we now know, has been going on for millions, nay, hundreds of millions of years), has finally exhausted all the possibilities of producing virulent or contagious diseases - which does not seem very likely.

Let me tell you the secret that has led me to my goal. My strength lies solely in my tenacity.

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.