War may be a natural expression of biological instincts and drives toward aggression in the human species. Natural impulses of anger, hostility, and territoriality (守卫地盘的天性) are expressed through acts of violence. Theses are all qualities that humans share with animals. Aggression is a kind of innate (天生的) survival mechanism, an instinct for self-preservation, that allows animals to defend themselves from threats to their existence. But, on the other hand, human violence shows evidence of being a learned behavior. In the case of human aggression, violence cannot be simply reduced to an instinct. The many expressions of human violence are always conditioned by social conventions that give shape to aggressive behavior. In human societies violence has a social function: It is a strategy for creating or destroying forms of social order. Religious traditions have taken a leading role in directing the powers of violence. We will look at the ritual and ethical (道德上的) patterns within which human violence has been directed.
    The violence within a society is controlled through institutions of law. The more developed a legal system becomes, the more society takes responsibility for the discovery, control, and punishment of violent acts. In most tribal societies the only means to deal with an act of violence is revenge. Each family group may have the responsibility for personally carrying out judgment and punishment upon the person who committed the offense. But in legal systems, the responsibility for revenge becomes depersonalized and diffused. The society assumes the responsibility for protecting individuals from violence. In cases where they cannot be protected, the society is responsible for imposing punishment. In a sate controlled legal system, individuals are removed from the cycle of revenge motivated by acts of violence, and the state assumes responsibility for their protection.
    The other side of a state legal apparatus is a state military apparatus. While the one protects the individual from violence, the other sacrifices the individual to violence in the interests of the state. In war the state affirms its supreme power over the individuals within its own borders. War is not simply a trial by combat to settle disputes between states; it is the moment when the state makes its most powerful demands upon its people for their recommitment, allegiance, and supreme sacrifice. Times of war test a community’s deepest religious and ethical commitments.