This book, part of the Shinrigaku series, is an abridged version of A Legacy of Lost Arts. It is designed to serve as a quick reference on the basic mental skills of the shinobi, but excludes the historical context found in Legacy. In its current form, it can be used as a checklist for the development and continued maintenance of the disciplines described, which are a defining component of ninjutsu. If these mind disciplines are ignored, the physical training in ninjutsu can become almost indistinguishable from the quotidian block-punch-and-throw combat arts. This in fact is already the case in those dojo that purport to teach ninjutsu. Of course, self-defense techniques and combat abilities are necessary skills, as is the ability to use traditional Japanese weapons-but ninjutsu is the art of Espionage! Where is the intelligence gathering? The surreptitious entry and exit methods? The covert strategies? The counters to the enemy's strategies? The invisible accomplishment of one's objectives? In short, what do these "ninjutsu" dojo and seminars offer to set themselves apart from the ubiquitous jujutsu or self-defense1 schools that teach the same or similar skills? Is it their black jujutsu uniforms or fancy "ninja" patches that make what they teach "ninjutsu?" While unarmed and armed fighting arts are a part of ninjutsu, the art relies on many more arts that are not being taught in dojo around the world. It is those arts that we will begin to introduce in this book.