There comes a time when the mind takes a higher plane of knowledge but can never prove how it got there.

Information is not knowledge.

It's not that I'm so smart; it's just that I stay with problems longer.

The difference between genius and stupidity is; genius has its limits.

Great spirits have always encountered violent opposition from mediocre minds.

Every serious scientific worker is painfully conscious ... of being relegated to an ever-narrowing sphere of knowledge.