Many people seem to find it important to identify some quality whether positive or negative as the true essence of human beings. I find this need to essentialize our nature perplexing. To me it seems quite obvious that humans are all of these things (and more). We are capable of extreme acts of brutality and cruelty and extraordinary acts of altruism and generosity. We are both cooperative and competitive. We live, by and large, peacefully with one another, but we are also violent, as evidenced by murder, rape, and war. We are mimetic but are also capable of thinking for ourselves. We are often superstitious and believe in unfounded things but can be rational and are excellent at reasoning. We can be reactive and impulsive but are also able to harness the qualities of self-discipline, restraint, and self-control.
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We are basically animals by nature and this characteristic manifests itself in the form of wars, fights and revenge battles in one form or another.
Hence the philosophy of ahimsa advocated by Gautam Buddha and Mahatma Gandhi makes them stand out as greats amongst other human beings.