Why should I not simply do whatever I want to do?
To those who don't have a conscience, this is exactly how they think. A rapist doesn't care that the act is illegal, they'll do it anyways. Consequences do not stop a person from doing that which they are hell bent on doing anyways. To me, the thing that prevents us from acting out like this is empathy. This is where the Golden Rule comes in, a basic concept that is echoed in all the religions of the earth. If I do not like pain inflicted on me, why would I find it appealing to inflict it on another? The fact that laws are not a deterrent to crime, but rather the punishment after comitting it, shows that we can not prevent a sick mind from acting out their most carnal of instincts, we can only hope to contain them for the greater social good. I believe in moral relativism, for the simple fact that it is true. What is commonly accepted by some is abhorrent to others. What makes it so? As NewSense said, it is what is considered normal by the community.