"If we were bees, ants, or Lacedaemonian warriors, to whom personal fear does not exist and cowardice is the most shameful thing in the world, warring would go on forever. But luckily we are only men —…"

"The human mind is not capable of grasping the universe. We are like a little child entering a huge library. The walls are covered to the ceilings with books in many different tongues. The child knows …"

"If we were to pursue the idea to its logical conclusion, we would have to assume that every thought, every feeling, every sensation is somehow connected with an elementary process in the brain, with a…"

"The important thing is not to stop questioning."

"The best way to escape from the problem is to solve it."