Violence does not exist only in human society; it is an expression of the need for survival in all living things. A wolf is violent toward sheep; so is a bull fighting another bull for the right to procreate.
For better or worse, human beings are part of nature; as animals, we too have to eat other living beings. It is quite easy for us to accept this kind of violence, since it is linked with the survival of the species.
However, things become more complicated when we consider that human beings can perpetrate violence for purposes that go beyond the sheer need for survival. Let us consider the need for space: all living things need some space to live, and that includes human beings individually and in groups (tribes or nations). But sometimes humans claim the right over the same land (as in the case of the Israelis and Palestinians), and hence conflicts appear.
In some cases, the line between survival and greed is crossed (though sometimes it is difficult to define that line). Other impulses such as greed, ambition, the search for power or frustration projected on others may lie behind aggression. It is difficult to say whether these traits exist in animals, or only in humans, but humans have certainly carried this very far. Human beings are the only living beings on earth whose search for more has led them to lose balance with the environment and their fellow human beings.
Fortunately, human beings are also the only beings that have the capacity to distinguish right from wrong. It is this moral capacity that could allow humans to mitigate violence to the extent where they would only perpetrate it as self-defence, or in matters of life and death. Yet in order to do this they would need to learn how to respect each other’s right to exist and be ‘oneself’. The answer to this should be education, but something of a deeper kind than the one we learn in schools today (since they have failed miserably at preventing violence or greed). It should begin with knowing ourselves, our needs and desires, then progressively extend this knowledge to our community, our nation, humanity, and nature. If we learn to respect first ourselves, and then the others, perhaps there would be much less violence in the world.