The unknown is the largest need of the intellect.

Most new discoveries are suddenly-seen things that were always there.

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

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

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

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

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

Science is a cemetery of dead ideas.

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

How gloriously legible are the constellations of the heavens!

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

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

Appearances are a glimpse of the obscure.