If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living
Henri PoincareMost striking at first is the appearance of sudden illumination, a manifest sign of long unconscious prior work.
Henri PoincareA first fact should surprise us, or rather would surprise us if we were not used to it. How does it happen there are people who do not understand mathematics? If mathematics invokes only the rules of logic, such as are accepted by all normal minds...how does it come about that so many persons are here refractory?
Henri Poincare