I suppose, Thomas Langdon, that the colors of the world depend upon one's own eyes.

What I call green may appear to you like the color of blue to me.

Now, Arthur really sees all these things that he's telling about, because he has the eye of the mind with which to see them.

I've quit saying that people don't see things, because I don't see 'em myself." "Good for you, Professor," said Langdon.

"That's quite a lecture you gave me, long though not windy, and I accept it.