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

Appearances are a glimpse of the obscure.

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

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

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

How gloriously legible are the constellations of the heavens!

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

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

What one man can invent another can discover.

There are truths that prove their discoverers witless.