It is my hope that you will never have to read this book, because the subject matter that it deals with is truly vile. However, sometimes you have to be around that one person who keeps suggesting that there's an essential difference between races. That is when you break out this book. This book clearly and methodically outlines the history of racism as well of the (lack of ) science surrounding race and genetics. It is a great guide not for debunking racists because racists tend not to care about facts, but for demonstrating the unreasonableness of it to others.