The philosophies of Buddhism and Zen, and to a lesser extent Confucianism and Shinto, influenced the samurai culture. Zen meditation became an important teaching due to it offering a process to calm one's mind. The Buddhist concept of reincarnation and rebirth led samurai to abandon torture and needless killing, while some samurai even gave up violence altogether and became Buddhist monks after realizing how fruitless their killings were. Some were killed as they came to terms with these realizations in the battlefield. The most defining role thatConfucianism played in samurai philosophy was to stress the importance of the lord-retainer relationship; this is, the loyalty that a samurai was required to show his lord.
Bushidō ("way of the warrior") was a term that began to appear in intellectual and nationalist discourse after the Japanese defeat of China in 1885 and of Russia in 1905 . Hagakure or "Hidden in Leaves" by Yamamoto Tsunetomo and Gorin no Sho or "Book of the Five Rings" by Miyamoto Musashi both written in the Tokugawa period (1603–1868)are theories often associated with Bushido and Zen philosophy.
The philosophies of Buddhism and Zen, and to a lesser extent Confucianism and Shinto, are attributed to the development of the samurai culture. "The notion that Zen is somehow related to Japanese culture in general,and bushido in particular, is familiar to Western students of Zen through the writings of D. T. Suzuki, no doubt the single most important figure in the spread of Zen in the West." 
In an account of Japan sent to Father Ignatius Loyola at Rome, drawn from the statements of Anger (Han-Siro's western name), Xavier describes the importance of honor to the Japanese (Letter preserved at College of Coimbra.):
"In the first place, the nation with which we have had to do here surpasses in goodness any of the nations lately discovered. I really think that among barbarous nations there can be none that has more natural goodness than the Japanese. They are of a kindly disposition, not at all given to cheating, wonderfully desirous of honour and rank. Honour with them is placed above everything else. There are a great many poor among them, but poverty is not a disgrace to any one. There is one thing among them of which I hardly know whether it is practised anywhere among Christians. The nobles, however poor they may be, receive the same honour from the rest as if they were rich".