Chance favours the trained mind.

Analogy cannot serve as proof.

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.

Do not promote what you can't explain, simplify, and prove early.

Luck favors the mind that is prepared.

The grandeur of the acts of men are measured by the inspiration from which they spring.

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.