Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Fascinating content, terrible writing

The content of this book is simply fascinating. Not only does it present a plausible solution to the Cambrian enigma, it also provides a huge amount of information on the role of color and eyesight in nature. The only drawback is that the writing style is extremely clumsy and sometimes the logic is very difficult to follow. The author should have teamed up with a professional writer.