Imagination:

Albert Einstein was a great German scientist who proposed many theories on quantum mechanics and quantum physics, he re-suggested the theory that light was made of particles. However, he was also very philosophical and spiritual. He respected everyone's views, no matter their background. He also encouraged people to think:
"Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand."