Burning a book is a matter of intent... I submit that a knee-jerk "NO" is just as irrational a response as burning a book because you disagree with it. In the case of Eragon, I wouldn't be burning it from malice, but from a desire to start a fire using the most appropriate material at hand. If I had newspaper, I'd use that, but Eragon would be far preferable to any other bound paper I own.

Besides, I could just burn the last half a few pages at a time, and no one sensible would ever notice.

Also, book-burning isn't as big a deal as it used to be. Consider the relative scarcity of books when it WAS a big deal, as opposed to now when it would take a Herculean effort to burn even a fraction of the copies of Eragon that are out there.

For thought: Gluing the pages together is functionally identical to burning the book.