This isn't a bad book. It's a quick and easy read. The title is misleading.
Saying it's Hank Reinhardt's, has a lot to say about knives, or is a "practical and illustrated guide to knife fighting" are all pushing it.
What H.R. had to say in this book is short and minimal. He has some entertaining stories, and -touches- on a couple of topics not mentioned in other books.
Sure, there's plenty of admonishment that knife fighting is bad business (is there such a book that doesn't?). There is a long, completely obsolete section on the carry and opening of pocket knives from the days before every pocket knife had a clip and one handed opening capability. There is a section on "wounds" that has almost nothing to say about knives or wounds; you can literally learn more about knife wounds from the scattered stories before that chapter. There is even one illustration that will give you deja vu; it takes up 90% of one page, and it is copied as filler further along in the book. You'll also hear a fair amount about H.R.'s knife collection. This book also references a few times to George Silver's (a 16th c. martial arts instructor) page on knife combat, and they make the completely erroneous claim that the shortsword he preferred was the precursor to the smallsword, showing a complete lack of knowledge about their favorite source.
The middle of the book is a praising eulogy by several friends/acquaintances of Mr. Reinhardt, as is the preface, which also explains that his portion of the book is pieced together notes he never felt like publishing. Nothing I'd pay money to read if I wasn't his friend.
Finally, the most substantial single portion of the book is an actual attempt at a knife fighting book, but it's by a guy by the name of Greg Phillips. The first portion of which, Choosing a Knife, is very much an opinion piece, much of which I strongly disagreed with, and at least some of which is demonstrably false, which started me off on a tentative foot about what this guy really knows about knives. Then there's a short but practical enough bit on acquiring basics without instruction. But then the part you think would teach you the nominal "practical" knife fighting is actually anything but: it is a chapter on fighting with large kukris, bowies, and daggers! After which, there's a token page on mindset. Much of this work seems to be on the kind of informal backyard self instruction and sparring H.R. was known for (not that that's a bad thing).
So, was I better off for having read this? I'll say that if it was the first one I ever read, and I was new to the subject, I would've come away with more than when I started. However, there are books on the topic out there that will leave you with more than this one.