The eternal mystery of the world is its comprehensibility.

The unknown is the largest need of the intellect.

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.

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

The discovery of a new dish does more for human happiness than the discovery of a star.

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

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.

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

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