The unknown is the largest need of the intellect.

The eternal mystery of the world is its comprehensibility.

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

I am tormented with an everlasting itch for things remote. I love to sail forbidden seas and land on barbarous coasts.

A man of genius makes no mistakes. His errors are volitional and are the portals of discovery.

The atavistic urge toward danger persists and its satisfaction is called adventure.

They are ill discoverers that think there is no land, when they can see nothing but sea.

Nature has planted in our minds an insatiable desire to seek the truth.

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

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

What one man can invent another can discover.

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

True originality consists not in a new manner but in a new vision.