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.

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

Without theory, practice is but routine born of habit. Theory alone can bring forth and develop the spirit of invention. ... [Do not] share the opinion of those narrow minds who disdain everything in science which has not an immediate application. ... A theoretical discovery has but the merit of its existence: it awakens hope, and that is all. But let it be cultivated, let it grow, and you will see what it will become.

Science belongs to no one country.

Chance favors the prepared mind.

Chance favors those who are prepared.

I give them experiments and they respond with speeches.