Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Correct spelling is a PRINCIPAL requirement for a writing guide...

In theory, I would completely approve of the idea of enlivening this useful classic writing guide with illustrations. However, having examined this particular edition, I can't get past the horrifying error at the top of page 147, in which the spelling "principle" is substituted for the correct form of the adjective "principal," as in "main," or "chief." This passage is supposedly from the introduction to the book's first edition by William Strunk, Jr., who would have made no such mistake. (It is however a common one, to judge by its appearance in at least one of the Amazon reader reviews of this book).Didn't anyone at The Penguin Press proofread this book? To introduce this type of basic error into a revered reference book is an unforgiveable disservice to the masters of writing. Strunk and White must be rolling over in their graves...