To bring one's self to believe in a truth that has just dawned upon one is the first step towards progress; to persuade others is the second.

The nights seem to me too long... I am often scolded by Madame Pasteur, but I tell her I shall lead her to fame.

Messieurs, c'est les microbes qui auront le dernier mot." (Gentlemen, it is the microbes who will have the last word.)

The controls of life are structured as forms and nuclear arrangements, in a relation with the motions of the universe.

When I approach a child, he inspires in me two sentiments; tenderness for what he is, and respect for what he may become.

Chance favors the prepared mind.

Science knows no country, because knowledge belongs to humanity, and is the torch which illuminates the world. Science is the highest personification of the nation because that nation will remain the first which carries the furthest the works of thought and intelligence.