HP Lovecraft was a serious student of the work done within his chosen genre, and this book is evidence. Though written long, long ago, and discussing some works that are long (and undeservedly)-forgotten, the tenets that the Old Gent sets forth in this treatise still hold true to this day. Anyone seeking to work within the horror genre MUST have it. Those who wish to further their understanding of that genre, or of the Cthulhu Mythos specifically, SHOULD have it. The book itself is well-written in HPLs inimitable florid style, slim, and easily digestible, with the chapters clearly marked off so that you can take your time chewing on the concepts discussed therein.