The unknown is the largest need of the intellect.

What one man can invent another can discover.

Appearances are a glimpse of the obscure.

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

There are truths that prove their discoverers witless.

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

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

Science is a cemetery of dead ideas.

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

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