The nature of man is the basis of an ethical system. The primary virtue is rationality. The proper beneficiary is oneself. Man can choose between good and evil actions. Meaning that in any contest, there are winners and losers.
Man can create.
Man can make new things where none previously existed. Man's life is not zero-sum unless he chooses it to be. A cheetah is not called evil because it kills in order to survive. A man who kills to survive is considered evil because he has a choice in his actions. Everyone has the right to his or her own life.