External objects produce decided effects upon the brain. A man shut up between four walls soon loses the power to associate words and ideas together. How many prisoners in solitary confinement become idiots, if not mad, for want of exercise for the thinking faculty!

The human mind delights in grand conceptions of supernatural beings. And the sea is precisely their best vehicle, the only medium through which these giants (against which terrestrial animals, such as elephants or rhinoceroses, are as nothing) can be produced or developed

I am nothing to you but Captain Nemo; and you and your companions are nothing to me but the passengers of the Nautilus.

We now know most things that can be measured in this world, except the bounds of human ambition!

What use are the best of arguments when they can be destroyed by force?

On the surface of the ocean, men wage war and destroy each other; but down here, just a few feet beneath the surface, there is a calm and peace, unmolested by man

Wherever he saw a hole he always wanted to know the depth of it. To him this was important.