Book excerpt: Aiki is the power of harmony, of all beings, all things working together. Aikido—a modern Japanese martial art unique in its synthesis of classic forms with a well-defined spiritual base—offers a key to the art of living naturally and unselfishly in a complicated world. This book explains it in reference to the founder's philosophy of mind—and action. In addition, the history of aikido's prewar development as a non-competitive new martial art is described, with a consideration of its international role.