All questions on morality boil
All questions on morality boil down the fulcrum of this one issue: whether my will takes precedence over yours. If I am evil, it's precisely because I feel, or appear to feel, as if my opinions, feelings, and actions are better than how others would want them. Evil is just selfishness, and good is just selflessness. But if I say that selflessness is good, aren't I being selfish? If I desire others to be selfless, I'm asking others to put aside their own desires for the sake of what I endorse. This is why we developed collective communication mediums such as morality, religion, and social norms. This way we can invoke some other, imaginary, third party x as being the one that desires a certain will. This way we can convince ourselves that we are not selfish, but are only upholding a "higher order" or a "doing what's right." This cannot be further from the truth, for it is our personal faith in our specific understanding of a specific system of values that is taking precedence over that of others'. This is why Sartre always failed (or subconsciously refrained) from ever developing a system of morality. There is no a priori system of morality because in the end it's a homo sapien sapien who looks at the system, accepts it, and then enforces his will over other super-chimpanzees.