When thinking about Zen, yoga, and shamanism, we must not forget their social context. Zen was essential to the samurai class in Japan. Yoga was geared toward the Kshatriya caste in India. And shamanism was crucial to the tribal leaders all around the globe in both chase and war. Differences between these three systems come from three different social orders, but they provide the essential link between spiritual power and real power through all stages of social development. The mastery of perilous emotions, such as fear or anger or desire, lies at the bottom of all three systems. They must be eradicated for a warrior to fulfill his duties to the best of his ability. Among such emotions, the fear of death is primary and most difficult to handle by a human being. Spiritual guidance is therefore required, and this is where Zen, yoga, and shamanism come into the picture. Contemporary neglect of the social foundations of these spiritual systems is thus both ridiculous and pernicious, for the core that they share will come to the fore whenever social upheaval threatens.