In teaching man, experimental science results in lessening his pride more and more by proving to him every day that primary causes, like the objective reality of things, will be hidden from him forever and that he can only know relations.

Progress is achieved by exchanging our theories for new ones which go further than the old, until we find one based on a larger number of facts. ... Theories are only hypotheses, verified by more or less numerous facts. Those verified by the most facts are the best, but even then they are never final, never to be absolutely believed.

A discovery is generally an unforeseen relation not included in theory.

In these researches I followed the principles of the experimental method that we have established, i.e., that, in presence of a well-noted, new fact which contradicts a theory, instead of keeping the theory and abandoning the fact, I should keep and study the fact, and I hastened to give up the theory.

The true worth of an experimenter consists in his pursuing not only what he seeks in his experiment, but also what he did not seek.

Those who do not know the torment of the unknown cannot have the joy of discovery.

We must never make experiments to confirm our ideas, but simply to control them.