The article considers the nature of mastery in martial arts (bugei) and the method to obtain it according to the treatise by Issai Chozan (1659–1741), Tengu Geijutsu Ron (Discourse of Tengu on the Art [of the Sword], 1729). This text is a unique phenomenon in the martial arts literature of the Edo period. A work written with a mass readership in mind, it was received by martial artists as an epiphany and remains a part of the canon of the Japanese bugei until now. The topic of mind and methods of controlling its state occupies the central place in the treatise. The sections focusing on this topic contain a comprehensive analysis of the empirical, “incorrect” state of mind (shin), which is juxtaposed with the state of “true mind” (shintai).According to one version, these sections were actually written not by Issai Chozan, but by one of the greatest Japanese Confucian scholars of the 17th century, a representative of the Japanese Wang Yangming school, Kumazawa Banzan (1619–1691), which, probably, explains the depth in which the topic of mind is covered. The Tengu Geijutsu Ron persuasively shows that mastery in martial arts is the result of achieving the state of “true mind” (shintai), bringing in the right state the pneuma-ki, mastering the technique of battle, training the body, grasping the “nature” (sei) of the weapon used and obtaining the ability to “follow” this nature. Issei Chozan notes that, in the system “mind – pneuma – body,” mind occupies the top, commanding place, directing the ki, which, in turn, directs the body, but the process of achieving mastery is based on using feedback in this system.