SPECIAL OFFER THE DEFENSIVE EDGE VOLUME 1 BOOK DE Volume 1 Knife Self Defense Book I will sign all advanced copies. The Defensive Edge Volume 1 book is the beginning of series on knife self defense that will soon be available for schools to finally offer as a curriculum to their students.. I designed this book to be a supplement to any martial art school regardless of style or system. We live in a world full of knives. Lets arm our students with a healthy knowledge of what to do if confronted by an edged weapon.