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

The unknown is the largest need of the intellect.

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

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

Appearances are a glimpse of the obscure.

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

One sees great things from the valley; only small things from the peak.

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

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

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