Scott Westerfeld then asked, "How is reading an illustrated book different from reading one without pictures?"
I could talk about this for days. As I have but a minute right now, I posted this:
The first line of Alice's Adventures in Wonderland by Lewis Carroll reads as follows:
Alice was beginning to get very tired of sitting by her sister on the bank and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, "and what is the use of a book," thought Alice, "without pictures or conversations?"
I've always enjoyed this book and related to the main character. However, even when I was a kid, I would cite this as one big difference between Alice and moi: I found books to be quite useful even without pictures, and had no problem digesting long classics without pictures. ;-)
Unless it employs abstract illustrations, an illustrated book tends to solidify the looks of the characters, making them look the same in the minds of all readers, while a picture-free book allows for more variations due to imagination.
Another quote from Alice:
(If you don't know what a Gryphon is, look at the picture.)
Instead of detailing the appearance of the Gryphon, the author relies upon the illustration to inform the reader.
It is of note that Charles Dodgson (aka Lewis Carroll) illustrated the original manuscript of Alice's Adventures Under Ground, before it was updated with John Tenniel's equally beautiful and iconic illustrations, as seen in the first official - and now classic - published version.
For more about some of my favorite interior illustrations and book covers, read my article entitled Judging the Cover, published in 2007.
Learn more about my love for the novel Alice's Adventures in Wonderland and check out my Alice-related booklist.
Want an example of a solid novel with wonderful illustrations and broad appeal? Check out The Secret Journeys of Jack London by Christopher Golden and Tim Lebbon, illustrated by Greg Ruth. Wait until you meet the Wendigo.