"One must have a certain amount of daring to embark on a scientific career."

"You have not succeeded in your experiments, that is all there is to it."

"The more progress physical sciences make, the more they give us cause to believe that all phenomena are reducible to molecular forces."

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

"Posterity will one day laugh at the sublime foolishness of the modern materialistic philosophy."