God has given me a mule-like stubbornness to stick with a difficult problem and the intuitive powers to conceptualize complex hypothetical situations in my mind.

True religion is real living; living with all one's soul, with all one's goodness and righteousness.

The only thing we can be certain of in this life is that we can be certain of nothing.

I have remained a simple fellow who asks nothing of the world; only my youth is gone - the enchanting youth that forever walks on air.

Common sense is nothing more than a deposit of prejudices laid down by the mind before you reach eighteen.

Classical thermodynamics ... is the only physical theory of universal content which I am convinced ... will never be overthrown.

Imagination is more powerful than knowledge.