Intuition is given only to him who has undergone long preparation to receive it.

Chance favors the prepared mind.

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.

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

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

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.

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