There is no such thing as a special category of science called applied science; there is science and its applications, which are related to one another as the fruit is related to the tree that has borne it.

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

How do you know that the incessant progress of science will not compel scientists to consider that life has existed during eternity, and not matter?

These are the living springs of great thoughts and great actions. Everything grows clear in the reflections from the Infinite.

Where observation is concerned, chance favors only the prepared mind.

I am on the edge of mysteries and the veil is getting thinner and thinner.

To demonstrate experimentally that a microscopic organism actually is the cause of a disease and the agent of contagion, I know no other way, in the present state of Science, than to subject the microbe (the new and happy term introduced by M. Sédillot) to the method of cultivation out of the body.