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

Since the most ancient times, all men, and particularly those who endeavored in the practice of medicine, have brought closer together two natural phenomena of capital importance: illness or fever and fermentation.

I give them experiments and they respond with speeches.

One does not ask of one who suffers: What is your country and what is your religion? One merely says: You suffer, that is enough for me.

Science belongs to no one country.

There does not exist a category of science to which one can give the name applied science. There are sciences and the applications of science, bound together as the fruit of the tree which bears it.

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