Knowledge is dead; the school, however, serves the living.

One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike -- and yet it is the most precious thing we have.

The sceptic will say, 'It may well be true that this system of equations is reasonable from a logical standpoint, but this does not prove that it corresponds to nature.' You are right, dear sceptic. Experience alone can decide on truth.

The measure of intelligence is the ability to change.

But nature did not deem it her business to make the discovery of her laws easy for us.

The really valuable method of thought to arrive at a logically coherent system is intuition.

It is our American habit if we find the foundations of our educational structure unsatisfactory to add another story or wing.