Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: One of the very best

This is definitely one of the best SF books I've ever read, and I have re-read it many times. One thing that bothers me is how the heck this book can be out of print. It's one of those classics that should always be available to new readers, and don't worry about it being dated because it was written in the fifties - nobody's running around with a slide rule here. Just a wonderful, wonderful book.