Even 10 years after the book has been published it still has been used and commented on. The author uses this chapter to clarify the misconceptions that previous readers have had. They believed that it was impossible for the accidental error to be removed. Surprisingly, some of the things that the author put into the book so long ago are still true. The author uses this chapter to discus what is still true and what needs to be corrected.
Conceptual integrity is still as important.