Posterity will one day laugh at the sublime foolishness of the modern materialistic philosophy. The more I study nature, the more I stand amazed at the work of the Creator. I pray while I am engaged at my work in the laboratory.

Do not put forward anything that you cannot prove by experimentation.

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.

Science knows no country because it is the light that iluminates the world

In the realm of scientific observation, luck is granted only to those who are prepared.

Herrmann Pidoux and Armand Trousseau stated 'Disease exists within us, because of us, and through us', Pasteur did not entirely disagree, 'This is true for certain diseases', he wrote cautiously, only to add immediately: 'I do not think that it is true for all of them'.

It is not the germs we need worry about. It is our inner terrain.