What Were the Beliefs of the Samurai?
The medieval Japanese warriors known as the samurai have been a fascination source for people throughout the world for centuries. For a good reason – they were among the most elite warriors in human history. The samurai are renowned for several reasons, which include their efficiency in battle, their well-crafted katana swords, and most importantly, their honor code is known as bushido. It was the code of bushido that set the samurai apart from other contemporary warrior groups and gave them their reasons to fight. Without the bushido code, the samurai would have just another one of the many warrior classes in history.
Bushido was an extremely complex worldview, but it shared many attributes with the honor code of medieval European knights for the sake of comparison. The code of bushido was followed faithfully by the samurai. Every detail of how they conducted themselves in battle was dictated by the code, including some of the following matters: the types of weapons that were allowed, the treatment of enemies, and how death was preferred over cowardice, considered the worst form of dishonor. Bushido also required that samurai spare women and children from violence and never engaged in wanton cruelty of animals. Besides these important ideas, the samurai were also expected to respect their culture and national traditions and to show the utmost respect for their lord and shoguns, even to the point of following them after death. An examination of the bushido code reveals that it is actually the result of three different but complementary Eastern religious and philosophical traditions – Shintoism, Confucianism, and Zen Buddhism.
What is a Samurai?
The samurai rose to prominence in Japan gradually during the twelfth century AD, making themselves known when they helped repulse the Mongols in the thirteenth century. Before the Mongols attempted their amphibious invasion of Japan, a highly militarized government took power in the Japanese city of Kamakura that established a bakufu or shogunate. The Kamakura shogunate defeated all but one other power in Japan by giving special concessions to the buke or warrior class during the Gempei War (1180-1185). The result was Japan’s first military government based in Kamakura, although the shogunate never ruled over a unified Japan. 
Once the buke class had attained prominence during the Gempei War, they did not relinquish that power and gradually became the most important class in Japan. By the time of Japan’s civil war in the sixteenth century, known as the Senogku, the buke was primarily referred to as samurai. The samurai led the daimyos, who were feudal lords in the brutal war that determined Japan's leadership. The samurai were a privileged class set apart from all others in Japanese society, but they were also held to a higher standard.  Finally, in 1603, the Sengoku came to an end when Tokugawa Ieyasu (1542-1616) unified Japan under his rule and established the Tokugawa shogunate, which lasted until 1867.
What were the Samurai's Religious Beliefs?
Of the three major religious and philosophical traditions that comprised the samurai belief system and influenced the code of bushido, Shinto was the oldest. Shintoism is essentially the ancient, native religious traditions of Japan practiced in a highly ritualistic setting. The Shinto pantheon was full of many gods and goddesses who lived in the forests, mountains, water bodies, and even the air. Interestingly, none of these deities were considered omnipotent. The Shinto pantheon's deities' powers could only be harnessed by priests who knew the proper incantations and rituals.
The rituals were so sometimes so esoteric that the meanings of the words in many of the incantations have long since been forgotten, but the perceived power of the act remains. Shinto priests perform their arcane rituals before important life events, which in medieval Japan would include battles.  Ultimately, it was Shintoism that gave the samurai their strong belief in tradition and the will to fight for their homeland.
What was the Samurai's Philosophy?
Although the samurai were spiritual warriors, they were also quite practical, which was no doubt at least partially the result of their belief in the philosophy of Confucianism. Confucianism's philosophy is named for the Chinese philosopher Kong (555-479 BC) – referred to in the Western world as Confucius – a civil servant and perhaps the Far East’s best-known philosopher. Confucianism stresses the importance of leading an ethical life, which includes unwavering respect for authority. The philosophy became quite popular at the court of many Chinese dynasties and eventually spread to Korea and Japan. The samurai enthusiastically embraced Confucian ideals due to the advocacy of what they believed was the natural hierarchy of man. Their Shinto gods established the order when they created the world, but Confucius articulated how the Japanese should view their shoguns, daimyos, and samurai. To the samurai, loyalty to superiors was never questioned.
Shinto gave the samurai something to fight for, and Confucianism established many of the rules in which they lived their lives. Still, Zen Buddhism gave them their moral compass and truly made them spiritual warriors instead of bloodthirsty marauders. Buddhism originated in India in the fifth century BC and then quickly spread throughout the Far East. During the eighth century AD, a form of Buddhism known as Chan made its way across the Sea of Japan and was embraced by the Japanese, who called the sect Zen.  Zen was different than many of the older Buddhist sects because it placed more emphasis on reaching enlightenment through meditation than on the study of the Buddha’s sutras or sayings, but it did not disregard the place of scholarship in the religion.
Foremost among Zen ideology were the Buddhist ideas of samsara, which is the idea of continual rebirths and karma. Karma is essentially a spiritual scorecard whereby an individual’s deeds, both good and bad, follow them from life to life and determine certain obstacles and rewards that one will face. To reduce one’s karma, the samurai were taught to follow the Noble Eightfold Path of Buddhism, which teaches one to practice the right actions, thoughts, etc. These ideas gave the samurai their respect for life. They were more than likely a big factor because the samurai initiated few atrocities against civilians during their long history. Although Zen helped spiritually ground the samurai, it did not make them weak and, in many ways, actually made them better warriors.
The samurai were able to use Zen's meditation practices to focus all of their mental faculties on becoming better warriors. Numerous texts describe how the samurai used the Zen mindset to eliminate all distractions and use their minds over matter. The late sixteenth/early seventeenth century samurai and philosopher Miyamoto Musashi incorporated many Zen ideas into his classic treatise of proper samurai warfare, The Book of Five Rings. The book is full of many Zen-inspired platitudes for erudite samurai, including the following:
“In order not to have your mind off to one side, it is necessary to place it in the center and move it calmly so that it does not cease to move even in moments of change.” 
What were the martial aspects of the Samurai?
Zen's martial aspects were also promoted by Japanese Buddhist monks, namely Eisai (1141-1215), who believed that Zen could be used to protect Japan from outsiders. According to Eisai, those who violated the morality of Zen “must not be allowed to walk on the king’s land, and must not be allowed to drink the king’s water.”  Although Eisai and other Zen monks believed violence was needed at times, they also thought that one should only do so when necessary and should never partake of violence for the sake of violence. Eisai also wrote that shoguns and samurai who followed the proper morality put forth by Zen would be rewarded in their future lives:
“Every one of them became king by means of past karma generated by having served five hundred Buddhas. . . From this passage, know that all kings upon hearing the true dharma will accept it and have faith in it.” 
What is the importance of Shinto, Confucianism, Zen, and Bushido for the Samurai?
The combination of Shintoism, Confucianism, and Zen Buddhism formed the samurai bushido warrior code. Although the samurai followed this code from the beginning of their existence, it was not codified until after the Sengoku in the seventeenth century.  Besides the individual elements that each philosophy brought to the bushido code, there were also additional components that were unique to the code, particularly the practice of seppuku. The practice of seppuku, which was heavily influenced by Confucianism, held that if a samurai brings dishonor to himself, his family, or his lord in any way, then he must commit ritual suicide by disembowelment.
A good samurai was also expected to take his life upon the death of his feudal lord. The bushido code helped give the samurai the discipline they have become known for and, for the most part, eliminated the wanton destruction of property and the murder of innocent civilians during any of their military campaigns. 
Many military historians consider the samurai to be among the most elite warriors in human history. Although the samurai were indeed excellent fighters on the battlefield and some were great strategists and tacticians, the true secret of their success was derived from their unique system of beliefs. At the core of the samurai, beliefs was their honor code known as bushido. Still, the bushido code was just the natural result of the three most important religions and philosophies the samurai followed – Shintoism, Confucianism, and Zen Buddhism. The Shinto beliefs connected the samurai to their people and land, while Confucianism taught them to respect authority and Japan's established social and political hierarchy. Finally, Zen Buddhism gave the samurai the morals that allowed them to be effective warriors without atrocities. Zen also gave the samurai the ability to better focus in combat and to practice the timeless adage of “mind over matter.”
Related DailyHistory.org Articles
- Mass, Jeffrey P. “Kamakura Bakufu.” Warrior Rule in Japan. Edited by Marius B. Jansen. (Cambridge, U.K.: Cambridge University Press, 1995), pgs. 1-4
- Friday, Karl F. “Bushido or Bull? A Medieval Historian’s Perspective on the Imperial Army and the Japanese Warrior Tradition.” The History Teacher. 27 (1994) p.343
- Aoki, Michiko Y. Ancient Myths and Early History of Japan: A Cultural Foundation. (New York: Exposition Press, 1974), p. 125-27
- Friday, p. 341
- Eisai. “Zen for National Defense.” In Buddhist Scriptures. Edited by Donald S. Lopez Junior. (London: Penguin Books, 2004), p. 323
- Mushashi, Miyamoto. The Complete Book of the Five Rings. Translated by Kenji Tokitsu. (Boston: Shambala, 2010), p. 46
- Eisai, p. 321
- Eisai, p. 323
- Friday, p. 340
- Friday, p. 346