The eternal mystery of the world is its comprehensibility.

What one man can invent another can discover.

Every man takes the limits of his own field of vision for the limits of the world.

Research is formalized curiosity. It is poking and prying with a purpose. 

When they shout “Long live progress,” always ask, “Progress of what?”

The unknown is the largest need of the intellect.

I learned to make my mind large, as the universe is large, so that there is room for paradoxes.

Appearances are a glimpse of the obscure.

What one man can invent another can discover.

One doesn’t discover new lands without consenting to lose sight of the shore for a very long time.