Aikido is the peaceful martial art. There are no attacks in aikido, only defense, and this defense should be so gentle that even the attacker is delighted by it. It is an art that takes a lifetime to learn, and it gets increasingly fascinating by each year. This book presents the principles and fundamental concepts of aikido - deeply rooted in Eastern philosophy and the refined ideals of the samurai. The first part of the book examines the aikido principles of how to find the peaceful solution, and how to enjoy aikido practice to the fullest. The second part explains the Japanese concepts used in aikido, such as ki, life energy, tanden, the center, and many more. There is also a chapter about kototama, the spiritual cosmology that was central to the founder of aikido. The third part includes an aikido glossary. A revised edition of this book is published with the title "Aikido Principles: Basic Concepts of the Peaceful Martial Art." Stefan Stenudd is a Swedish aikido instructor, 7 dan Aikikai shihan, member of the Swedish Grading Committee, President of the Swedish Budo & Martial Arts Federation, and former Vice Chairman of the International Aikido Federation. He has practiced aikido since 1972. He is also a writer of both fiction and non-fiction.