People make the mistake of talking about 'natural laws.' There are no natural laws. There are only temporary habits of nature.

Aristotle discovered all the half-truths which were necessary to the creation of science.

The worst that happened to men of science was that Galileo suffered an honorable detention and a mild reproof, before dying peacefully in his bed.

It is impossible not to feel stirred at the thought of the emotions of man at certain historic moments of adventure and discovery - Columbus when he first saw the Western shore, Pizarro when he stared at the Pacific Ocean, Franklin when the electric spark came from the string of his kite, Galileo when he first turned his telescope to the heavens. Such moments are also granted to students in the abstract regions of thought, and high among them must be placed the morning when Descartes lay in bed and invented the method of co-ordinate geometry.

The whole of mathematics consists in the organization of a series of aids to the imagination in the process of reasoning.

But harmony is limitation. Thus rightness of limitation is essential for growth of reality. Unlimited possibility and abstract creativity can procure nothing.

All practical teachers know that education is a patient process of mastery of details, minute by minute, hour by hour, day by day.