Civil war and religion in medieval Japan and medieval Europe: War for the Gods, emotions at death and treason

To compare and contrast medieval Japan and medieval Western Europe allows one to discover three things. First, analogous to Catholic holy war, in Japan becomes visible a potential for war (albeit seldom actualised) for the sake, quite surprisingly, of Buddhism. Second, the different role played by emotions during war: in Europe, when vicious (and motivated by emotions such as greed, ambition or lust), they endanger the victors; thus the concern for right emotions foster, to a point, proper behavior during war; in Japan, however, the focus is on the emotions of the defeated, which may hamper a good reincarnation and produce vengeful spirits harmful to the victors and to the community at large. Finally, while Japanese warriors could and often did switch sides, the archipelago did not know for centuries anything approaching the European concept of treason, ideally punished with the highest cruelty, hated and feared to the point of generating collective paranoia and conspiracy theories. Western treason was (and is still) a secularised offspring of the Christian belief in the internal enemy of the Church, the false brethren. Arguably, the texture of the religions present in the two ensembles gave their specific form to these three aspects of warfare.