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'.

Whether our efforts are, or not, favored by life, let us be able to say, when we come near to the great goal, I have done what I could.

My opinion - nay more, my conviction - is that, in the present state of science, as you rightly say, spontaneous generation is a chimera; and it would be impossible for you to contradict me, for my experiments all stand forth to prove that spontaneous generation is a chimera.

The role of the infinitely small in nature is infinitely great.

Will opens the door to success, both brilliant and happy.

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

My present and most fixed opinion regarding the nature of alcoholic fermentation is this: The chemical act of fermentation is essentially a phenomenon correlative with a vital act, beginning and ending with the latter. I believe that there is never any alcoholic fermentation without their being simultaneously the organization, development, multiplication of the globules, or the pursued, continued life of globules which are already formed.